//    Copyright (C) 2023 Jakub Melka
//
//    This file is part of PDF4QT.
//
//    PDF4QT is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Lesser General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    with the written consent of the copyright owner, any later version.
//
//    PDF4QT is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public License
//    along with PDF4QT.  If not, see <https://www.gnu.org/licenses/>.

#include "pdfwidgetformmanager.h"
#include "pdfdrawwidget.h"
#include "pdftexteditpseudowidget.h"
#include "pdfdrawspacecontroller.h"
#include "pdfform.h"
#include "pdfpainterutils.h"
#include "pdfwidgetannotation.h"
#include "pdfdocumentbuilder.h"

#include <QKeyEvent>
#include <QMouseEvent>
#include <QApplication>
#include <QByteArray>
#include <QClipboard>
#include <QStyleOption>

namespace pdf
{

/// "Pseudo" widget, which is emulating list box. It can contain scrollbar.
class PDFListBoxPseudowidget
{
public:
    explicit PDFListBoxPseudowidget(PDFFormField::FieldFlags flags);

    using Options = PDFFormFieldChoice::Options;

    inline bool isReadonly() const { return m_flags.testFlag(PDFFormField::ReadOnly); }
    inline bool isMultiSelect() const { return m_flags.testFlag(PDFFormField::MultiSelect); }
    inline bool isCommitOnSelectionChange() const { return m_flags.testFlag(PDFFormField::CommitOnSelectionChange); }

    void shortcutOverrideEvent(QWidget* widget, QKeyEvent* event);
    void keyPressEvent(QWidget* widget, QKeyEvent* event);

    /// Sets widget appearance, such as font, font size, color, text alignment,
    /// and rectangle, in which widget resides on page (in page coordinates)
    /// \param appearance Appearance
    /// \param textAlignment Text alignment
    /// \param rect Widget rectangle in page coordinates
    /// \param options Options selectable by list box
    /// \param topIndex Index of first visible item
    void setAppearance(const PDFAnnotationDefaultAppearance& appearance,
                       Qt::Alignment textAlignment,
                       QRectF rect,
                       const Options& options,
                       int topIndex,
                       std::set<int> selection);

    /// Draw text edit using given parameters
    /// \param parameters Parameters
    void draw(AnnotationDrawParameters& parameters, bool edit) const;

    /// Sets current selection. If commit on selection change flag
    /// is set, then contents of the widgets are commited. New selection
    /// is not set, if field is readonly and \p force is false
    /// \param selection New selection
    /// \param force Set selection even if readonly
    void setSelection(std::set<int> selection, bool force);

    /// Returns active item selection
    const std::set<int>& getSelection() const { return m_selection; }

    /// Returns top index
    int getTopItemIndex() const { return m_topIndex; }

    /// Set top item index
    /// \param index Top item index
    void setTopItemIndex(int index);

    /// Scrolls the list box in such a way, that index is visible
    /// \param index Index to scroll to
    void scrollTo(int index);

    /// Returns valid index from index (i.e. index which ranges from first
    /// row to the last one). If index itself is valid, then it is returned.
    /// \param index Index, from which we want to get valid one
    int getValidIndex(int index) const;

    /// Returns true, if index is valid
    bool isValidIndex(int index) const { return index == getValidIndex(index); }

    /// Returns number of rows in the viewport
    int getViewportRowCount() const { return qFloor(m_widgetRect.height() / m_lineSpacing); }

    /// Returns item index from widget position (i.e. transforms
    /// point in the widget to the index of item, which is under the point)
    /// \param point Widget point
    int getIndexFromWidgetPosition(const QPointF& point) const;

    /// Sets current item and updates selection based on keyboard modifiers
    /// \param index New index
    /// \param modifiers Keyboard modifiers
    void setCurrentItem(int index, Qt::KeyboardModifiers modifiers);

    /// Returns text of selected item text. If no item is selected,
    /// or multiple items are selected, then empty string is returned.
    /// \returns Selected text
    QString getSelectedItemText() const;

    /// Returns true, if single item is selected
    bool isSingleItemSelected() const { return m_selection.size() == 1; }

    /// Returns index of option, in the list box option list.
    /// If option is not found, then -1 is returned.
    /// \param option Option
    int findOption(const QString& option) const;

    /// Sets widget appearance, such as font, font size, color, text alignment,
    /// and rectangle, in which widget resides on page (in page coordinates)
    /// \param font Font
    /// \param fontColor Font color
    /// \param textAlignment Text alignment
    /// \param rect Widget rectangle in page coordinates
    /// \param options Options selectable by list box
    /// \param topIndex Index of first visible item
    void initialize(QFont font, QColor fontColor, Qt::Alignment textAlignment, QRectF rect,
                    const Options& options, int topIndex, std::set<int> selection);

private:
    int getStartItemIndex() const { return 0; }
    int getEndItemIndex() const { return m_options.empty() ? 0 : int(m_options.size() - 1); }

    int getSingleStep() const { return 1; }
    int getPageStep() const { return qMax(getViewportRowCount() - 1, getSingleStep()); }

    /// Returns true, if row with this index is visible in the widget
    /// (it is in viewport).
    /// \param index Index
    bool isVisible(int index) const;

    /// Moves current item by offset (negative is up, positive is down)
    /// \param offset Offset
    /// \param modifiers Keyboard modifiers
    void moveCurrentItemIndexByOffset(int offset, Qt::KeyboardModifiers modifiers) { setCurrentItem(m_currentIndex + offset, modifiers); }

    /// Returns true, if list box has continuous selection
    bool hasContinuousSelection() const;

    /// Creates transformation matrix, which transforms widget coordinates to page coordinates
    QTransform createListBoxTransformMatrix() const;

    PDFFormField::FieldFlags m_flags;

    Options m_options;
    Qt::Alignment m_textAlignment = Qt::Alignment();
    int m_topIndex = 0;
    int m_currentIndex = 0;
    std::set<int> m_selection;
    QFont m_font;
    PDFReal m_lineSpacing = 0.0;
    QRectF m_widgetRect;
    QColor m_textColor;
};


/// Editor for button-like editors
class PDFFormFieldAbstractButtonEditor : public PDFFormFieldWidgetEditor
{
private:
    using BaseClass = PDFFormFieldWidgetEditor;

public:
    explicit PDFFormFieldAbstractButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldAbstractButtonEditor() = default;

    virtual void shortcutOverrideEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void keyPressEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void keyReleaseEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;

protected:
    virtual void click() = 0;
};

/// Editor for push buttons
class PDFFormFieldPushButtonEditor : public PDFFormFieldAbstractButtonEditor
{
private:
    using BaseClass = PDFFormFieldAbstractButtonEditor;

public:
    explicit PDFFormFieldPushButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldPushButtonEditor() = default;

protected:
    virtual void click() override;
};

/// Editor for check boxes or radio buttons
class PDFFormFieldCheckableButtonEditor : public PDFFormFieldAbstractButtonEditor
{
private:
    using BaseClass = PDFFormFieldAbstractButtonEditor;

public:
    explicit PDFFormFieldCheckableButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldCheckableButtonEditor() = default;

protected:
    virtual void click() override;
};

/// Editor for text fields
class PDFFormFieldTextBoxEditor : public PDFFormFieldWidgetEditor
{
private:
    using BaseClass = PDFFormFieldWidgetEditor;

public:
    explicit PDFFormFieldTextBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldTextBoxEditor() = default;

    virtual void shortcutOverrideEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void keyPressEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void reloadValue() override;
    virtual bool isEditorDrawEnabled() const override { return m_hasFocus; }
    virtual void draw(AnnotationDrawParameters& parameters, bool edit) const override;

    /// Initializes text edit using actual form field value,
    /// font, color for text edit appearance.
    /// \param textEdit Text editor
    void initializeTextEdit(PDFTextEditPseudowidget* textEdit) const;

protected:
    virtual void setFocusImpl(bool focused) override;

private:
    PDFTextEditPseudowidget m_textEdit;
};

/// Editor for combo boxes
class PDFFormFieldComboBoxEditor : public PDFFormFieldWidgetEditor
{
private:
    using BaseClass = PDFFormFieldWidgetEditor;

public:
    explicit PDFFormFieldComboBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldComboBoxEditor() = default;

    virtual void shortcutOverrideEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void keyPressEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void wheelEvent(QWidget* widget, QWheelEvent* event, const QPointF& mousePagePosition) override;
    virtual void reloadValue() override;
    virtual bool isEditorDrawEnabled() const override { return m_hasFocus; }
    virtual void draw(AnnotationDrawParameters& parameters, bool edit) const override;
    virtual QRectF getActiveEditorRectangle() const override;

    /// Initializes text edit using actual form field value,
    /// font, color for text edit appearance.
    /// \param textEdit Text editor
    void initializeTextEdit(PDFTextEditPseudowidget* textEdit) const;

    /// Initializes list box using actual form field  font, color for text edit appearance.
    /// This listbox is used when combo box is in "down" mode, displaying options.
    /// \param listBox List box
    void initializeListBox(PDFListBoxPseudowidget* listBox) const;

protected:
    virtual void setFocusImpl(bool focused) override;

private:
    static PDFFormField::FieldFlags getTextEditFlags(PDFFormField::FieldFlags flags);

    /// Updates list box selection based on current text. If current text
    /// corresponds to some item in the list box, then item is selected
    /// and scrolled to. If text is not found in the text box, then
    /// selection is cleared.
    void updateListBoxSelection();

    PDFTextEditPseudowidget m_textEdit;
    PDFListBoxPseudowidget m_listBox;
    QRectF m_listBoxPopupRectangle;
    QRectF m_dropDownButtonRectangle;
    bool m_listBoxVisible;
};

/// Editor for list boxes
class PDFFormFieldListBoxEditor : public PDFFormFieldWidgetEditor
{
private:
    using BaseClass = PDFFormFieldWidgetEditor;

public:
    explicit PDFFormFieldListBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget);
    virtual ~PDFFormFieldListBoxEditor() = default;

    virtual void shortcutOverrideEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void keyPressEvent(QWidget* widget, QKeyEvent* event) override;
    virtual void mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition) override;
    virtual void wheelEvent(QWidget* widget, QWheelEvent* event, const QPointF& mousePagePosition) override;
    virtual void reloadValue() override;
    virtual bool isEditorDrawEnabled() const override { return m_hasFocus; }
    virtual void draw(AnnotationDrawParameters& parameters, bool edit) const override;

    /// Initializes list box using actual form field value,
    /// font, color for text edit appearance.
    /// \param listBox List box
    void initializeListBox(PDFListBoxPseudowidget* listBox) const;

protected:
    virtual void setFocusImpl(bool focused) override;

private:
    /// Returns list of selected items parsed from the object.
    /// If object is invalid, empty selection is returned. Indices are
    /// primarily read from \p indices object, if it fails, indices
    /// are being read from \p value object.
    /// \param value Selection (string or array of strings)
    /// \param indices Selected indices
    std::set<int> getSelectedItems(PDFObject value, PDFObject indices) const;

    /// Commits data to the PDF document
    void commit();

    PDFListBoxPseudowidget m_listBox;
};

PDFWidgetFormManager::PDFWidgetFormManager(PDFDrawWidgetProxy* proxy, QObject* parent) :
    BaseClass(parent),
    m_annotationManager(nullptr),
    m_proxy(proxy),
    m_focusedEditor(nullptr)
{
    Q_ASSERT(proxy);
}

PDFWidgetAnnotationManager* PDFWidgetFormManager::getAnnotationManager() const
{
    return m_annotationManager;
}

void PDFWidgetFormManager::setAnnotationManager(PDFWidgetAnnotationManager* annotationManager)
{
    m_annotationManager = annotationManager;
}

void PDFWidgetFormManager::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    if (m_focusedEditor)
    {
        m_focusedEditor->shortcutOverrideEvent(widget, event);
    }
}

void PDFWidgetFormManager::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    if (m_focusedEditor)
    {
        m_focusedEditor->keyPressEvent(widget, event);
    }
}

void PDFWidgetFormManager::keyReleaseEvent(QWidget* widget, QKeyEvent* event)
{
    if (m_focusedEditor)
    {
        m_focusedEditor->keyReleaseEvent(widget, event);
    }
}

void PDFWidgetFormManager::mousePressEvent(QWidget* widget, QMouseEvent* event)
{
    if (!hasForm())
    {
        return;
    }

    MouseEventInfo info = getMouseEventInfo(widget, event->pos());
    if (info.isValid())
    {
        Q_ASSERT(info.editor);

        // We try to set focus on editor
        if (event->button() == Qt::LeftButton)
        {
            setFocusToEditor(info.editor);
        }

        info.editor->mousePressEvent(widget, event, info.mousePosition);
        grabMouse(info, event);
    }
    else if (!isMouseGrabbed())
    {
        // Mouse is not grabbed, user clicked elsewhere, unfocus editor
        setFocusToEditor(nullptr);
    }
}

void PDFWidgetFormManager::mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event)
{
    if (!hasForm())
    {
        return;
    }

    MouseEventInfo info = getMouseEventInfo(widget, event->pos());
    if (info.isValid())
    {
        Q_ASSERT(info.editor);
        info.editor->mouseDoubleClickEvent(widget, event, info.mousePosition);

        // If mouse is grabbed, then event is accepted always (because
        // we get Press event, when we grabbed the mouse, then we will
        // wait for corresponding release event while all mouse move events
        // will be accepted, even if editor doesn't accept them.
        if (isMouseGrabbed())
        {
            event->accept();
        }
    }
}

void PDFWidgetFormManager::mouseReleaseEvent(QWidget* widget, QMouseEvent* event)
{
    if (!hasForm())
    {
        return;
    }

    MouseEventInfo info = getMouseEventInfo(widget, event->pos());
    if (info.isValid())
    {
        Q_ASSERT(info.editor);
        info.editor->mouseReleaseEvent(widget, event, info.mousePosition);
        ungrabMouse(info, event);
    }
}

void PDFWidgetFormManager::mouseMoveEvent(QWidget* widget, QMouseEvent* event)
{
    if (!hasForm())
    {
        return;
    }

    MouseEventInfo info = getMouseEventInfo(widget, event->pos());
    if (info.isValid())
    {
        Q_ASSERT(info.editor);
        info.editor->mouseMoveEvent(widget, event, info.mousePosition);

        // If mouse is grabbed, then event is accepted always (because
        // we get Press event, when we grabbed the mouse, then we will
        // wait for corresponding release event while all mouse move events
        // will be accepted, even if editor doesn't accept them.
        if (isMouseGrabbed())
        {
            event->accept();
        }

        if (hasFormFieldWidgetText(info.editor->getWidgetAnnotation()))
        {
            m_mouseCursor = QCursor(Qt::IBeamCursor);
        }
        else
        {
            m_mouseCursor = QCursor(Qt::ArrowCursor);
        }
    }
    else
    {
        m_mouseCursor = std::nullopt;
    }
}

void PDFWidgetFormManager::wheelEvent(QWidget* widget, QWheelEvent* event)
{
    if (!hasForm())
    {
        return;
    }

    MouseEventInfo info = getMouseEventInfo(widget, event->position().toPoint());
    if (info.isValid())
    {
        Q_ASSERT(info.editor);
        info.editor->wheelEvent(widget, event, info.mousePosition);

        // We will accept mouse wheel events, if we are grabbing the mouse.
        // We do not want to zoom in/zoom out while grabbing.
        if (isMouseGrabbed())
        {
            event->accept();
        }
    }
}

void PDFWidgetFormManager::grabMouse(const MouseEventInfo& info, QMouseEvent* event)
{
    if (event->type() == QEvent::MouseButtonDblClick)
    {
        // Double clicks doesn't grab the mouse
        return;
    }

    Q_ASSERT(event->type() == QEvent::MouseButtonPress);

    if (isMouseGrabbed())
    {
        // If mouse is already grabbed, then when new mouse button is pressed,
        // we just increase nesting level and accept the mouse event. We are
        // accepting all mouse events, if mouse is grabbed.
        ++m_mouseGrabInfo.mouseGrabNesting;
        event->accept();
    }
    else if (event->isAccepted())
    {
        // Event is accepted and we are not grabbing the mouse. We must start
        // grabbing the mouse.
        Q_ASSERT(m_mouseGrabInfo.mouseGrabNesting == 0);
        ++m_mouseGrabInfo.mouseGrabNesting;
        m_mouseGrabInfo.info = info;
    }
}

PDFWidgetFormManager::MouseEventInfo PDFWidgetFormManager::getMouseEventInfo(QWidget* widget, QPoint point)
{
    MouseEventInfo result;

    if (isMouseGrabbed())
    {
        result = m_mouseGrabInfo.info;
        result.mousePosition = result.deviceToWidget.map(point);
        return result;
    }

    std::vector<PDFInteger> currentPages = m_proxy->getWidget()->getDrawWidget()->getCurrentPages();

    if (!m_annotationManager->hasAnyPageAnnotation(currentPages))
    {
        // All pages doesn't have annotation
        return result;
    }

    PDFWidgetSnapshot snapshot = m_proxy->getSnapshot();
    for (const PDFWidgetSnapshot::SnapshotItem& snapshotItem : snapshot.items)
    {
        const PDFAnnotationManager::PageAnnotations& pageAnnotations = m_annotationManager->getPageAnnotations(snapshotItem.pageIndex);
        for (const PDFAnnotationManager::PageAnnotation& pageAnnotation : pageAnnotations.annotations)
        {
            if (pageAnnotation.annotation->isReplyTo())
            {
                // Annotation is reply to another annotation, do not interact with it
                continue;
            }

            if (pageAnnotation.annotation->getType() != AnnotationType::Widget)
            {
                // Annotation is not widget annotation (form field), do not interact with it
                continue;
            }

            if (PDFFormField* formField = getFormFieldForWidget(pageAnnotation.annotation->getSelfReference()))
            {
                PDFFormFieldWidgetEditor* editor = getEditor(formField);
                QRectF annotationRect = editor ? editor->getActiveEditorRectangle() : QRectF();
                if (!annotationRect.isValid())
                {
                    annotationRect = pageAnnotation.annotation->getRectangle();
                }
                QTransform widgetToDevice = m_annotationManager->prepareTransformations(snapshotItem.pageToDeviceMatrix, widget, pageAnnotation.annotation->getEffectiveFlags(), getDocument()->getCatalog()->getPage(snapshotItem.pageIndex), annotationRect);

                QPainterPath path;
                path.addRect(annotationRect);
                path = widgetToDevice.map(path);

                if (path.contains(point))
                {
                    result.formField = formField;
                    result.deviceToWidget = widgetToDevice.inverted();
                    result.mousePosition = result.deviceToWidget.map(point);
                    result.editor = editor;
                    return result;
                }
            }
        }
    }

    return result;
}

const std::optional<QCursor>& PDFWidgetFormManager::getCursor() const
{
    return m_mouseCursor;
}

void PDFWidgetFormManager::ungrabMouse(const MouseEventInfo& info, QMouseEvent* event)
{
    Q_UNUSED(info);
    Q_ASSERT(event->type() == QEvent::MouseButtonRelease);

    if (isMouseGrabbed())
    {
        // Mouse is being grabbed, decrease nesting level. We must also accept
        // mouse release event, because mouse is being grabbed.
        --m_mouseGrabInfo.mouseGrabNesting;
        event->accept();

        if (!isMouseGrabbed())
        {
            m_mouseGrabInfo.info = MouseEventInfo();
        }
    }

    Q_ASSERT(m_mouseGrabInfo.mouseGrabNesting >= 0);
}

int PDFWidgetFormManager::getInputPriority() const
{
    return FormPriority;
}

QString PDFWidgetFormManager::getTooltip() const
{
    return QString();
}

bool PDFWidgetFormManager::focusNextPrevFormField(bool next)
{
    if (m_widgetEditors.empty())
    {
        return false;
    }

    std::vector<PDFFormFieldWidgetEditor*>::const_iterator newFocusIterator = m_widgetEditors.cend();

    if (!m_focusedEditor)
    {
        // We are setting a new focus
        if (next)
        {
            newFocusIterator = m_widgetEditors.cbegin();
        }
        else
        {
            newFocusIterator = std::prev(m_widgetEditors.cend());
        }
    }
    else
    {
        std::vector<PDFFormFieldWidgetEditor*>::const_iterator it = std::find(m_widgetEditors.cbegin(), m_widgetEditors.cend(), m_focusedEditor);
        Q_ASSERT(it != m_widgetEditors.cend());

        if (next)
        {
            newFocusIterator = std::next(it);
        }
        else if (it != m_widgetEditors.cbegin())
        {
            newFocusIterator = std::prev(it);
        }
    }

    if (newFocusIterator != m_widgetEditors.cend())
    {
        setFocusToEditor(*newFocusIterator);
        return true;
    }
    else
    {
        // Jakub Melka: We must remove focus out of editor, because
        setFocusToEditor(nullptr);
    }

    return false;
}

void PDFWidgetFormManager::clearEditors()
{
    qDeleteAll(m_widgetEditors);
    m_widgetEditors.clear();
}

void PDFWidgetFormManager::updateFormWidgetEditors()
{
    setFocusToEditor(nullptr);
    clearEditors();

    for (PDFFormWidget widget : getWidgets())
    {
        const PDFFormField* formField = widget.getParent();
        switch (formField->getFieldType())
        {
            case PDFFormField::FieldType::Button:
            {
                Q_ASSERT(dynamic_cast<const PDFFormFieldButton*>(formField));
                const PDFFormFieldButton* formFieldButton = static_cast<const PDFFormFieldButton*>(formField);
                switch (formFieldButton->getButtonType())
                {
                    case PDFFormFieldButton::ButtonType::PushButton:
                    {
                        m_widgetEditors.push_back(new PDFFormFieldPushButtonEditor(this, widget));
                        break;
                    }

                    case PDFFormFieldButton::ButtonType::RadioButton:
                    case PDFFormFieldButton::ButtonType::CheckBox:
                    {
                        m_widgetEditors.push_back(new PDFFormFieldCheckableButtonEditor(this, widget));
                        break;
                    }

                    default:
                        Q_ASSERT(false);
                        break;
                }

                break;
            }

            case PDFFormField::FieldType::Text:
            {
                m_widgetEditors.push_back(new PDFFormFieldTextBoxEditor(this, widget));
                break;
            }

            case PDFFormField::FieldType::Choice:
            {
                Q_ASSERT(dynamic_cast<const PDFFormFieldChoice*>(formField));
                const PDFFormFieldChoice* formFieldChoice = static_cast<const PDFFormFieldChoice*>(formField);
                if (formFieldChoice->isComboBox())
                {
                    m_widgetEditors.push_back(new PDFFormFieldComboBoxEditor(this, widget));
                }
                else if (formFieldChoice->isListBox())
                {
                    m_widgetEditors.push_back(new PDFFormFieldListBoxEditor(this, widget));
                }
                else
                {
                    // Uknown field choice
                    Q_ASSERT(false);
                }

                break;
            }

            case PDFFormField::FieldType::Signature:
                // Signature fields doesn't have editor
                break;

            default:
                Q_ASSERT(false);
                break;
        }
    }
}

void PDFWidgetFormManager::setFocusToEditor(PDFFormFieldWidgetEditor* editor)
{
    if (m_focusedEditor != editor)
    {
        if (m_focusedEditor)
        {
            m_focusedEditor->setFocus(false);
        }

        m_focusedEditor = editor;

        if (m_focusedEditor)
        {
            m_focusedEditor->setFocus(true);
        }

        // Request repaint, because focus changed
        Q_ASSERT(m_proxy);
        m_proxy->repaintNeeded();
    }
}

bool PDFWidgetFormManager::isFocused(PDFObjectReference widget) const
{
    if (m_focusedEditor)
    {
        return m_focusedEditor->getWidgetAnnotation() == widget;
    }

    return false;
}

PDFWidgetFormManager::~PDFWidgetFormManager()
{
    clearEditors();
}

void PDFWidgetFormManager::updateFieldValues()
{
    BaseClass::updateFieldValues();

    if (getDocument())
    {
        for (PDFFormFieldWidgetEditor* editor : m_widgetEditors)
        {
            editor->reloadValue();
        }
    }
}

PDFFormFieldWidgetEditor* PDFWidgetFormManager::getEditor(const PDFFormField* formField) const
{
    for (PDFFormFieldWidgetEditor* editor : m_widgetEditors)
    {
        if (editor->getFormField() == formField)
        {
            return editor;
        }
    }

    return nullptr;
}

PDFFormFieldWidgetEditor::PDFFormFieldWidgetEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    m_formManager(formManager),
    m_formWidget(formWidget),
    m_hasFocus(false)
{
    Q_ASSERT(m_formManager);
}

void PDFFormFieldWidgetEditor::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
}

void PDFFormFieldWidgetEditor::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
}

void PDFFormFieldWidgetEditor::keyReleaseEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
}

void PDFFormFieldWidgetEditor::mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
    Q_UNUSED(mousePagePosition);
}

void PDFFormFieldWidgetEditor::mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
    Q_UNUSED(mousePagePosition);
}

void PDFFormFieldWidgetEditor::mouseReleaseEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
    Q_UNUSED(mousePagePosition);
}

void PDFFormFieldWidgetEditor::mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
    Q_UNUSED(mousePagePosition);
}

void PDFFormFieldWidgetEditor::wheelEvent(QWidget* widget, QWheelEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(event);
    Q_UNUSED(mousePagePosition);
}

void PDFFormFieldWidgetEditor::setFocus(bool hasFocus)
{
    if (m_hasFocus != hasFocus)
    {
        m_hasFocus = hasFocus;
        setFocusImpl(m_hasFocus);
    }
}

void PDFFormFieldWidgetEditor::draw(AnnotationDrawParameters& parameters, bool edit) const
{
    Q_UNUSED(parameters);
    Q_UNUSED(edit)
}

void PDFFormFieldWidgetEditor::performKeypadNavigation(QWidget* widget, QKeyEvent* event)
{
    int key = event->key();

    const bool isLeft = key == Qt::Key_Left;
    const bool isRight = key == Qt::Key_Right;
    const bool isDown = key == Qt::Key_Down;
    const bool isHorizontal = isLeft || isRight;

    Qt::NavigationMode navigationMode = Qt::NavigationModeKeypadDirectional;
#ifdef QT_KEYPAD_NAVIGATION
    navigationMode = QApplication::navigationMode();
#endif

    switch (navigationMode)
    {
        case Qt::NavigationModeKeypadTabOrder:
        {
            // According the Qt's documentation, Up/Down arrows are used
            // to change focus. So, if user pressed Left/Right, we must
            // ignore this event.
            if (isHorizontal)
            {
                return;
            }
            break;
        }

        case Qt::NavigationModeKeypadDirectional:
            // Default behaviour
            break;

        default:
            // Nothing happens
            return;
    }

    bool next = false;
    if (isHorizontal)
    {
        switch (widget->layoutDirection())
        {
            case Qt::LeftToRight:
            case Qt::LayoutDirectionAuto:
                next = isRight;
                break;

            case Qt::RightToLeft:
                next = isLeft;
                break;

            default:
                Q_ASSERT(false);
                break;
        }
    }
    else
    {
        // Vertical
        next = isDown;
    }

    m_formManager->focusNextPrevFormField(next);
}

PDFFormFieldPushButtonEditor::PDFFormFieldPushButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget)
{

}

PDFFormFieldAbstractButtonEditor::PDFFormFieldAbstractButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget)
{

}

void PDFFormFieldAbstractButtonEditor::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    switch (event->key())
    {
        case Qt::Key_Enter:
        case Qt::Key_Return:
        case Qt::Key_Left:
        case Qt::Key_Right:
        case Qt::Key_Up:
        case Qt::Key_Down:
        {
            event->accept();
            break;
        }

        default:
            break;
    }
}

void PDFFormFieldAbstractButtonEditor::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    switch (event->key())
    {
        case Qt::Key_Enter:
        case Qt::Key_Return:
        {
            click();
            event->accept();
            break;
        }

        case Qt::Key_Left:
        case Qt::Key_Right:
        case Qt::Key_Up:
        case Qt::Key_Down:
        {
            performKeypadNavigation(widget, event);
            break;
        }

        default:
            break;
    }
}

void PDFFormFieldAbstractButtonEditor::keyReleaseEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    switch (event->key())
    {
        case Qt::Key_Select:
        case Qt::Key_Space:
        {
            click();
            event->accept();
            break;
        }

        default:
            break;
    }
}

void PDFFormFieldAbstractButtonEditor::mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(widget);
    Q_UNUSED(mousePagePosition);

    if (event->button() == Qt::LeftButton)
    {
        click();
        event->accept();
    }
}

void PDFFormFieldPushButtonEditor::click()
{
    if (const PDFAction* mousePressAction = m_formManager->getAction(PDFAnnotationAdditionalActions::MousePressed, getFormWidget()))
    {
        Q_EMIT m_formManager->actionTriggered(mousePressAction);
    }
    else if (const PDFAction* defaultAction = m_formManager->getAction(PDFAnnotationAdditionalActions::Default, getFormWidget()))
    {
        Q_EMIT m_formManager->actionTriggered(defaultAction);
    }
}

PDFFormFieldCheckableButtonEditor::PDFFormFieldCheckableButtonEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget)
{

}

void PDFFormFieldCheckableButtonEditor::click()
{
    QByteArray newState;

    // First, check current state of form field
    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());
    QByteArray state = loader.readName(m_formWidget.getParent()->getValue());
    QByteArray onState = PDFFormFieldButton::getOnAppearanceState(m_formManager, &m_formWidget);
    if (state != onState)
    {
        newState = onState;
    }
    else
    {
        newState = PDFFormFieldButton::getOffAppearanceState(m_formManager, &m_formWidget);
    }

    // We have a new state, try to apply it to form field
    PDFFormField::SetValueParameters parameters;
    parameters.formManager = m_formManager;
    parameters.invokingWidget = m_formWidget.getWidget();
    parameters.invokingFormField = m_formWidget.getParent();
    parameters.scope = PDFFormField::SetValueParameters::Scope::User;
    parameters.value = PDFObject::createName(qMove(newState));
    m_formManager->setFormFieldValue(parameters);
}

PDFFormFieldComboBoxEditor::PDFFormFieldComboBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget),
    m_textEdit(getTextEditFlags(formWidget.getParent()->getFlags())),
    m_listBox(formWidget.getParent()->getFlags()),
    m_listBoxVisible(false)
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    initializeTextEdit(&m_textEdit);

    QFontMetricsF fontMetrics(m_textEdit.getFont());
    const qreal lineSpacing = fontMetrics.lineSpacing();

    const int listBoxItems = qMin(7, int(parentField->getOptions().size()));
    QRectF comboBoxRectangle = m_formManager->getWidgetRectangle(m_formWidget);
    QRectF listBoxPopupRectangle = comboBoxRectangle;
    listBoxPopupRectangle.translate(0, -lineSpacing * (listBoxItems));
    listBoxPopupRectangle.setHeight(lineSpacing * listBoxItems);
    m_listBoxPopupRectangle = listBoxPopupRectangle;
    m_dropDownButtonRectangle = comboBoxRectangle;
    m_dropDownButtonRectangle.setLeft(m_dropDownButtonRectangle.right() - m_dropDownButtonRectangle.height());
    initializeListBox(&m_listBox);
}

void PDFFormFieldComboBoxEditor::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    if (!m_hasFocus || !m_listBoxVisible)
    {
        m_textEdit.shortcutOverrideEvent(widget, event);
    }
    else
    {
        m_listBox.shortcutOverrideEvent(widget, event);
    }
}

void PDFFormFieldComboBoxEditor::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    Q_ASSERT(!m_textEdit.isMultiline());

    if ((event->key() == Qt::Key_Enter || event->key() == Qt::Key_Return))
    {
        // If popup list box is shown, then use text and hide it,
        // otherwise close the editor.
        if (m_listBoxVisible)
        {
            if (m_listBox.isSingleItemSelected())
            {
                m_textEdit.setText(m_listBox.getSelectedItemText());
            }
            m_listBoxVisible = false;
        }
        else
        {
            m_formManager->setFocusToEditor(nullptr);
        }

        event->accept();
    }
    else if (event->key() == Qt::Key_Escape)
    {
        // If popup list box is shown, hide it, if not, cancel the editing
        if (m_listBoxVisible)
        {
            m_listBoxVisible = false;
        }
        else
        {
            reloadValue();
            m_formManager->setFocusToEditor(nullptr);
        }
        event->accept();
    }
    else if (!m_listBoxVisible)
    {
        m_textEdit.keyPressEvent(widget, event);
    }
    else
    {
        m_listBox.keyPressEvent(widget, event);
    }

    if (event->isAccepted())
    {
        widget->update();
    }
}

void PDFFormFieldComboBoxEditor::mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->button() == Qt::LeftButton && m_hasFocus)
    {
        // If popup list box is visible, delegate mouse click to
        // this list box only.
        if (m_listBoxVisible)
        {
            const int index = m_listBox.getIndexFromWidgetPosition(mousePagePosition);
            m_listBox.setCurrentItem(index, event->modifiers());

            if (m_listBox.isSingleItemSelected())
            {
                m_textEdit.setText(m_listBox.getSelectedItemText());
            }

            m_listBoxVisible = false;
        }
        else
        {
            // Do we click popup button?
            if (m_dropDownButtonRectangle.contains(mousePagePosition))
            {
                m_listBoxVisible = true;
                updateListBoxSelection();
            }
            else
            {
                const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
                m_textEdit.setCursorPosition(cursorPosition, event->modifiers() & Qt::ShiftModifier);
            }
        }

        event->accept();
        widget->update();
    }
}

void PDFFormFieldComboBoxEditor::mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->button() == Qt::LeftButton)
    {
        const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
        m_textEdit.setCursorPosition(cursorPosition, false);
        m_textEdit.setCursorPosition(m_textEdit.getCursorWordBackward(), false);
        m_textEdit.setCursorPosition(m_textEdit.getCursorWordForward(), true);

        event->accept();
        widget->update();
    }
}

void PDFFormFieldComboBoxEditor::mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    // We must test, if left mouse button is pressed while
    // we are moving the mouse - if yes, then select the text.
    if (event->buttons() & Qt::LeftButton && !m_listBoxVisible)
    {
        const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
        m_textEdit.setCursorPosition(cursorPosition, true);

        event->accept();
        widget->update();
    }
}

void PDFFormFieldComboBoxEditor::wheelEvent(QWidget* widget, QWheelEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(mousePagePosition);

    if (m_listBoxVisible)
    {
        if (event->angleDelta().y() < 0)
        {
            m_listBox.scrollTo(m_listBox.getValidIndex(m_listBox.getTopItemIndex() + m_listBox.getViewportRowCount()));
        }
        else
        {
            m_listBox.scrollTo(m_listBox.getValidIndex(m_listBox.getTopItemIndex() - 1));
        }

        widget->update();
        event->accept();
    }
}

void PDFFormFieldComboBoxEditor::updateListBoxSelection()
{
    QString text = m_textEdit.getText();

    const int index = m_listBox.findOption(text);
    if (m_listBox.isValidIndex(index))
    {
        m_listBox.setSelection({ index }, true);
        m_listBox.scrollTo(index);
    }
    else
    {
        m_listBox.setTopItemIndex(0);
        m_listBox.setSelection({ }, true);
    }
}

void PDFFormFieldComboBoxEditor::reloadValue()
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());
    m_textEdit.setText(loader.readTextString(m_formWidget.getParent()->getValue(), QString()));

    m_listBoxVisible = false;
}

void PDFFormFieldComboBoxEditor::draw(AnnotationDrawParameters& parameters, bool edit) const
{
    if (edit)
    {
        // Draw text edit always
        {
            PDFPainterStateGuard guard(parameters.painter);
            m_textEdit.draw(parameters, true);
        }

        // Draw down button
        {
            PDFPainterStateGuard guard(parameters.painter);

            parameters.painter->translate(m_dropDownButtonRectangle.bottomLeft());
            parameters.painter->scale(1.0, -1.0);

            QStyleOption option;
            option.state = QStyle::State_Enabled;
            option.rect = QRect(0, 0, qFloor(m_dropDownButtonRectangle.width()), qFloor(m_dropDownButtonRectangle.height()));
            QApplication::style()->drawPrimitive(QStyle::PE_IndicatorButtonDropDown, &option, parameters.painter, nullptr);
        }

        if (m_listBoxVisible)
        {
            PDFPainterStateGuard guard(parameters.painter);

            AnnotationDrawParameters listBoxParameters = parameters;
            listBoxParameters.boundingRectangle = m_listBoxPopupRectangle;

            QColor color = parameters.colorConvertor.convert(Qt::white, true, false);
            listBoxParameters.painter->fillRect(listBoxParameters.boundingRectangle, color);

            m_listBox.draw(listBoxParameters, true);
        }
    }
    else
    {
        // Draw static contents
        PDFTextEditPseudowidget pseudowidget(m_formWidget.getParent()->getFlags());
        initializeTextEdit(&pseudowidget);
        pseudowidget.draw(parameters, false);
    }
}

QRectF PDFFormFieldComboBoxEditor::getActiveEditorRectangle() const
{
    if (m_hasFocus && m_listBoxVisible)
    {
        return m_textEdit.getWidgetRect().united(m_listBoxPopupRectangle);
    }

    return QRectF();
}

void PDFFormFieldComboBoxEditor::initializeTextEdit(PDFTextEditPseudowidget* textEdit) const
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());

    QByteArray defaultAppearance = m_formManager->getForm()->getDefaultAppearance().value_or(QByteArray());
    Qt::Alignment alignment = m_formManager->getForm()->getDefaultAlignment();

    // Initialize text edit
    textEdit->setAppearance(PDFAnnotationDefaultAppearance::parse(defaultAppearance), alignment, m_formManager->getWidgetRectangle(m_formWidget), 0);
    textEdit->setText(loader.readTextString(parentField->getValue(), QString()));
}

void PDFFormFieldComboBoxEditor::initializeListBox(PDFListBoxPseudowidget* listBox) const
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    // Initialize popup list box
    listBox->initialize(m_textEdit.getFont(), m_textEdit.getFontColor(), m_formManager->getForm()->getDefaultAlignment(),  m_listBoxPopupRectangle, parentField->getOptions(), 0, { });
}

void PDFFormFieldComboBoxEditor::setFocusImpl(bool focused)
{
    if (focused)
    {
        m_textEdit.setCursorPosition(m_textEdit.getPositionEnd(), false);
        m_textEdit.performSelectAll();
    }
    else if (!m_formManager->isCommitDisabled())
    {
        // If text has been changed, then commit it
        PDFObject object = PDFObjectFactory::createTextString(m_textEdit.getText());

        if (object != m_formWidget.getParent()->getValue())
        {
            PDFFormField::SetValueParameters parameters;
            parameters.formManager = m_formManager;
            parameters.invokingWidget = m_formWidget.getWidget();
            parameters.invokingFormField = m_formWidget.getParent();
            parameters.scope = PDFFormField::SetValueParameters::Scope::User;
            parameters.value = qMove(object);
            m_formManager->setFormFieldValue(parameters);
        }
    }
}

PDFFormField::FieldFlags PDFFormFieldComboBoxEditor::getTextEditFlags(PDFFormField::FieldFlags flags)
{
    if (flags.testFlag(PDFFormField::ReadOnly) || !flags.testFlag(PDFFormField::Edit))
    {
        return PDFFormField::ReadOnly;
    }

    return PDFFormField::None;
}

void PDFFormFieldTextBoxEditor::initializeTextEdit(PDFTextEditPseudowidget* textEdit) const
{
    const PDFFormFieldText* parentField = dynamic_cast<const PDFFormFieldText*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());

    QByteArray defaultAppearance = parentField->getDefaultAppearance();
    if (defaultAppearance.isEmpty())
    {
        defaultAppearance = m_formManager->getForm()->getDefaultAppearance().value_or(QByteArray());
    }
    Qt::Alignment alignment = parentField->getAlignment();
    if (!(alignment & Qt::AlignHorizontal_Mask))
    {
        alignment |= m_formManager->getForm()->getDefaultAlignment() & Qt::AlignHorizontal_Mask;
    }

    // Initialize text edit
    textEdit->setAppearance(PDFAnnotationDefaultAppearance::parse(defaultAppearance), alignment, m_formManager->getWidgetRectangle(m_formWidget), parentField->getTextMaximalLength());
    textEdit->setText(loader.readTextString(parentField->getValue(), QString()));
}

void PDFFormFieldTextBoxEditor::setFocusImpl(bool focused)
{
    if (focused)
    {
        m_textEdit.setCursorPosition(m_textEdit.getPositionEnd(), false);
        m_textEdit.performSelectAll();
    }
    else if (!m_textEdit.isPassword() && !m_formManager->isCommitDisabled()) // Passwords are not saved in the document
    {
        // If text has been changed, then commit it
        PDFObject object = PDFObjectFactory::createTextString(m_textEdit.getText());

        if (object != m_formWidget.getParent()->getValue())
        {
            PDFFormField::SetValueParameters parameters;
            parameters.formManager = m_formManager;
            parameters.invokingWidget = m_formWidget.getWidget();
            parameters.invokingFormField = m_formWidget.getParent();
            parameters.scope = PDFFormField::SetValueParameters::Scope::User;
            parameters.value = qMove(object);
            m_formManager->setFormFieldValue(parameters);
        }
    }
}

PDFFormFieldTextBoxEditor::PDFFormFieldTextBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget),
    m_textEdit(formWidget.getParent()->getFlags())
{
    initializeTextEdit(&m_textEdit);
}

void PDFFormFieldTextBoxEditor::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    m_textEdit.shortcutOverrideEvent(widget, event);
}

void PDFFormFieldTextBoxEditor::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    if (!m_textEdit.isMultiline() && (event->key() == Qt::Key_Enter || event->key() == Qt::Key_Return))
    {
        // Commit the editor
        m_formManager->setFocusToEditor(nullptr);
        event->accept();
        return;
    }

    if (event->key() == Qt::Key_Escape)
    {
        // Cancel the editor
        reloadValue();
        m_formManager->setFocusToEditor(nullptr);
        event->accept();
        return;
    }

    m_textEdit.keyPressEvent(widget, event);

    if (event->isAccepted())
    {
        widget->update();
    }
}

void PDFFormFieldTextBoxEditor::mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->button() == Qt::LeftButton)
    {
        const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
        m_textEdit.setCursorPosition(cursorPosition, event->modifiers() & Qt::ShiftModifier);

        event->accept();
        widget->update();
    }
}

void PDFFormFieldTextBoxEditor::mouseDoubleClickEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->button() == Qt::LeftButton)
    {
        const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
        m_textEdit.setCursorPosition(cursorPosition, false);
        m_textEdit.setCursorPosition(m_textEdit.getCursorWordBackward(), false);
        m_textEdit.setCursorPosition(m_textEdit.getCursorWordForward(), true);

        event->accept();
        widget->update();
    }
}

void PDFFormFieldTextBoxEditor::mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    // We must test, if left mouse button is pressed while
    // we are moving the mouse - if yes, then select the text.
    if (event->buttons() & Qt::LeftButton)
    {
        const int cursorPosition = m_textEdit.getCursorPositionFromWidgetPosition(mousePagePosition, m_hasFocus);
        m_textEdit.setCursorPosition(cursorPosition, true);

        event->accept();
        widget->update();
    }
}

void PDFFormFieldTextBoxEditor::reloadValue()
{
    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());
    m_textEdit.setText(loader.readTextString(m_formWidget.getParent()->getValue(), QString()));
}

void PDFFormFieldTextBoxEditor::draw(AnnotationDrawParameters& parameters, bool edit) const
{
    if (edit)
    {
        m_textEdit.draw(parameters, true);
    }
    else
    {
        // Draw static contents
        PDFTextEditPseudowidget pseudowidget(m_formWidget.getParent()->getFlags());
        initializeTextEdit(&pseudowidget);
        pseudowidget.draw(parameters, false);
    }
}

PDFListBoxPseudowidget::PDFListBoxPseudowidget(PDFFormField::FieldFlags flags) :
    m_flags(flags),
    m_topIndex(0),
    m_currentIndex(0)
{

}

void PDFListBoxPseudowidget::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    if (event == QKeySequence::Copy)
    {
        event->accept();
        return;
    }

    if (event == QKeySequence::SelectAll)
    {
        // Select All can be processed only, if multiselection is allowed
        if (isMultiSelect())
        {
            event->accept();
        }
        return;
    }

    switch (event->key())
    {
        case Qt::Key_Home:
        case Qt::Key_End:
        case Qt::Key_Up:
        case Qt::Key_Down:
        case Qt::Key_PageUp:
        case Qt::Key_PageDown:
            event->accept();
            break;

        default:
            break;
    }
}

void PDFListBoxPseudowidget::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    event->accept();

    if (event == QKeySequence::Copy)
    {
        // Copy the item text
        if (m_currentIndex >= 0 && m_currentIndex < m_options.size())
        {
            QApplication::clipboard()->setText(m_options[m_currentIndex].userString, QClipboard::Clipboard);
        }
        return;
    }

    if (event == QKeySequence::SelectAll && isMultiSelect())
    {
        std::set<int> selection;
        for (int i = 0; i < m_options.size(); ++i)
        {
            selection.insert(i);
        }
        setSelection(qMove(selection), false);
        return;
    }

    switch (event->key())
    {
        case Qt::Key_Home:
            setCurrentItem(getStartItemIndex(), event->modifiers());
            break;

        case Qt::Key_End:
            setCurrentItem(getEndItemIndex(), event->modifiers());
            break;

        case Qt::Key_Up:
            moveCurrentItemIndexByOffset(-getSingleStep(), event->modifiers());
            break;

        case Qt::Key_Down:
            moveCurrentItemIndexByOffset(getSingleStep(), event->modifiers());
            break;

        case Qt::Key_PageUp:
            moveCurrentItemIndexByOffset(-getPageStep(), event->modifiers());
            break;

        case Qt::Key_PageDown:
            moveCurrentItemIndexByOffset(getPageStep(), event->modifiers());
            break;

        default:
            event->ignore();
            break;
    }
}

void PDFListBoxPseudowidget::initialize(QFont font, QColor fontColor, Qt::Alignment textAlignment, QRectF rect,
                                        const Options& options, int topIndex, std::set<int> selection)
{
    m_font = font;

    QFontMetricsF fontMetrics(m_font);
    m_lineSpacing = fontMetrics.lineSpacing();

    m_textColor = fontColor;
    if (!m_textColor.isValid())
    {
        m_textColor = Qt::black;
    }

    m_textAlignment = textAlignment;
    m_widgetRect = rect;
    m_options = options;
    m_topIndex = getValidIndex(topIndex);
    m_selection = qMove(selection);
    m_currentIndex = m_topIndex;
}

void PDFListBoxPseudowidget::setAppearance(const PDFAnnotationDefaultAppearance& appearance,
                                           Qt::Alignment textAlignment,
                                           QRectF rect,
                                           const PDFListBoxPseudowidget::Options& options,
                                           int topIndex,
                                           std::set<int> selection)
{
    // Set appearance
    qreal fontSize = appearance.getFontSize();
    if (qFuzzyIsNull(fontSize))
    {
        fontSize = qMax(rect.height() / qMax<qreal>(options.size(), 1), qreal(12.0));
    }

    QColor fontColor = appearance.getFontColor();

    QFont font(appearance.getFontName());
    font.setHintingPreference(QFont::PreferNoHinting);
    font.setPixelSize(qCeil(fontSize));
    font.setStyleStrategy(QFont::ForceOutline);

    initialize(font, fontColor, textAlignment, rect, options, topIndex, qMove(selection));
}

QTransform PDFListBoxPseudowidget::createListBoxTransformMatrix() const
{
    QTransform matrix;
    matrix.translate(m_widgetRect.left(), m_widgetRect.bottom());
    matrix.scale(1.0, -1.0);
    return matrix;
}

void PDFListBoxPseudowidget::draw(AnnotationDrawParameters& parameters, bool edit) const
{
    pdf::PDFPainterStateGuard guard(parameters.painter);

    if (!parameters.boundingRectangle.isValid())
    {
        parameters.boundingRectangle = parameters.annotation->getRectangle();
    }

    QPalette palette = QApplication::palette();
    QTransform matrix = createListBoxTransformMatrix();
    QPainter* painter = parameters.painter;

    if (edit)
    {
        pdf::PDFPainterStateGuard guard2(painter);
        painter->setPen(parameters.colorConvertor.convert(Qt::black, false, true));
        painter->setBrush(Qt::NoBrush);
        painter->drawRect(parameters.boundingRectangle);
    }

    painter->setClipRect(parameters.boundingRectangle, Qt::IntersectClip);
    painter->setWorldTransform(QTransform(matrix), true);
    painter->setPen(parameters.colorConvertor.convert(m_textColor, false, true));
    painter->setFont(m_font);

    QColor textColor = parameters.colorConvertor.convert(m_textColor, false, true);
    QColor highlightTextColor = parameters.colorConvertor.convert(palette.color(QPalette::HighlightedText), false, true);
    QColor highlightColor = parameters.colorConvertor.convert(palette.color(QPalette::Highlight), false, false);

    QRectF rect(0, 0, m_widgetRect.width(), m_lineSpacing);
    for (int i = m_topIndex; i < int(m_options.size()); ++i)
    {
        if (m_selection.count(i))
        {
            painter->fillRect(rect, highlightColor);
            painter->setPen(highlightTextColor);
        }
        else
        {
            painter->setPen(textColor);
        }

        painter->drawText(rect, m_textAlignment | Qt::TextSingleLine, m_options[i].userString);

        if (edit && m_currentIndex == i)
        {
            pdf::PDFPainterStateGuard guard2(painter);
            painter->setBrush(Qt::NoBrush);
            painter->setPen(Qt::DotLine);
            painter->drawRect(rect);
        }

        rect.translate(0, m_lineSpacing);
    }
}

void PDFListBoxPseudowidget::setSelection(std::set<int> selection, bool force)
{
    if (isReadonly() && !force)
    {
        // Field is readonly
        return;
    }

    // Jakub Melka: Here should be also commit, when flag CommitOnSelectionChange is set,
    // but we do it only, when widget loses focus (so no need to update appearance often).
    // I hope it will be OK.

    m_selection = qMove(selection);
}

void PDFListBoxPseudowidget::setTopItemIndex(int index)
{
    m_topIndex = getValidIndex(index);
}

bool PDFListBoxPseudowidget::isVisible(int index) const
{
    return index >= m_topIndex && index < m_topIndex + getViewportRowCount();
}

void PDFListBoxPseudowidget::scrollTo(int index)
{
    while (!isVisible(index))
    {
        if (index < m_topIndex)
        {
            --m_topIndex;
        }
        else
        {
            ++m_topIndex;
        }
    }
}

void PDFListBoxPseudowidget::setCurrentItem(int index, Qt::KeyboardModifiers modifiers)
{
    index = getValidIndex(index);

    if (m_currentIndex == index)
    {
        return;
    }

    std::set<int> newSelection;
    if (!isMultiSelect() || !modifiers.testFlag(Qt::ShiftModifier))
    {
        newSelection = { index };
    }
    else
    {
        int indexFrom = index;
        int indexTo = index;

        if (hasContinuousSelection())
        {
            indexFrom = qMin(index, *m_selection.begin());
            indexTo = qMax(index, *m_selection.rbegin());
        }
        else
        {
            indexFrom = qMin(index, m_currentIndex);
            indexTo = qMax(index, m_currentIndex);
        }

        for (int i = indexFrom; i <= indexTo; ++i)
        {
            newSelection.insert(i);
        }
    }

    m_currentIndex = index;
    setSelection(qMove(newSelection), false);
    scrollTo(m_currentIndex);
}

QString PDFListBoxPseudowidget::getSelectedItemText() const
{
    if (m_selection.size() == 1)
    {
        const int selectedIndex = *m_selection.begin();
        return m_options[selectedIndex].userString;
    }

    return QString();
}

int PDFListBoxPseudowidget::findOption(const QString& option) const
{
    auto it = std::find_if(m_options.cbegin(), m_options.cend(), [&option](const auto& currentOption) { return currentOption.userString == option; });
    if (it != m_options.cend())
    {
        return static_cast<int>(std::distance(m_options.cbegin(), it));
    }

    return -1;
}

bool PDFListBoxPseudowidget::hasContinuousSelection() const
{
    if (m_selection.empty())
    {
        return false;
    }

    return *m_selection.rbegin() - *m_selection.begin() + 1 == int(m_selection.size());
}

int PDFListBoxPseudowidget::getValidIndex(int index) const
{
    return qBound(getStartItemIndex(), index, getEndItemIndex());
}

int PDFListBoxPseudowidget::getIndexFromWidgetPosition(const QPointF& point) const
{
    QTransform widgetToPageMatrix = createListBoxTransformMatrix();
    QTransform pageToWidgetMatrix = widgetToPageMatrix.inverted();

    QPointF widgetPoint = pageToWidgetMatrix.map(point);
    const qreal y = widgetPoint.y();
    const int visualIndex = qFloor(y / m_lineSpacing);
    return m_topIndex + visualIndex;
}

PDFFormFieldListBoxEditor::PDFFormFieldListBoxEditor(PDFWidgetFormManager* formManager, PDFFormWidget formWidget) :
    BaseClass(formManager, formWidget),
    m_listBox(formWidget.getParent()->getFlags())
{
    initializeListBox(&m_listBox);
}

void PDFFormFieldListBoxEditor::shortcutOverrideEvent(QWidget* widget, QKeyEvent* event)
{
    Q_UNUSED(widget);

    m_listBox.shortcutOverrideEvent(widget, event);
}

void PDFFormFieldListBoxEditor::keyPressEvent(QWidget* widget, QKeyEvent* event)
{
    if ((event->key() == Qt::Key_Enter || event->key() == Qt::Key_Return))
    {
        // Commit the editor
        m_formManager->setFocusToEditor(nullptr);
        event->accept();
        return;
    }

    if (event->key() == Qt::Key_Escape)
    {
        // Cancel the editor
        reloadValue();
        m_formManager->setFocusToEditor(nullptr);
        event->accept();
        return;
    }

    m_listBox.keyPressEvent(widget, event);

    if (event->isAccepted())
    {
        widget->update();
    }
}

void PDFFormFieldListBoxEditor::mousePressEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->button() == Qt::LeftButton && m_hasFocus)
    {
        const int index = m_listBox.getIndexFromWidgetPosition(mousePagePosition);

        if (event->modifiers() & Qt::ControlModifier)
        {
            std::set<int> selection = m_listBox.getSelection();
            if (selection.count(index))
            {
                selection.erase(index);
            }
            else
            {
                selection.insert(index);
            }
            m_listBox.setSelection(qMove(selection), false);
        }
        else
        {
            m_listBox.setCurrentItem(index, event->modifiers());
        }

        event->accept();
        widget->update();
    }
}

void PDFFormFieldListBoxEditor::mouseMoveEvent(QWidget* widget, QMouseEvent* event, const QPointF& mousePagePosition)
{
    if (event->buttons() & Qt::LeftButton)
    {
        const int index = m_listBox.getIndexFromWidgetPosition(mousePagePosition);

        if (!(event->modifiers() & Qt::ControlModifier))
        {
            m_listBox.setCurrentItem(index, event->modifiers());

            event->accept();
            widget->update();
        }
    }
}

void PDFFormFieldListBoxEditor::wheelEvent(QWidget* widget, QWheelEvent* event, const QPointF& mousePagePosition)
{
    Q_UNUSED(mousePagePosition);

    if (m_hasFocus)
    {
        if (event->angleDelta().y() < 0)
        {
            m_listBox.scrollTo(m_listBox.getValidIndex(m_listBox.getTopItemIndex() + m_listBox.getViewportRowCount()));
        }
        else
        {
            m_listBox.scrollTo(m_listBox.getValidIndex(m_listBox.getTopItemIndex() - 1));
        }

        widget->update();
        event->accept();
    }
}

void PDFFormFieldListBoxEditor::reloadValue()
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    m_listBox.setTopItemIndex(parentField->getTopIndex());
    m_listBox.setSelection(getSelectedItems(parentField->getValue(), parentField->getSelection()), true);
}

void PDFFormFieldListBoxEditor::draw(AnnotationDrawParameters& parameters, bool edit) const
{
    if (edit)
    {
        m_listBox.draw(parameters, true);
    }
    else
    {
        // Draw static contents
        PDFListBoxPseudowidget pseudowidget(m_formWidget.getParent()->getFlags());
        initializeListBox(&pseudowidget);
        pseudowidget.draw(parameters, false);
    }
}

void PDFFormFieldListBoxEditor::initializeListBox(PDFListBoxPseudowidget* listBox) const
{
    const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
    Q_ASSERT(parentField);

    listBox->setAppearance(PDFAnnotationDefaultAppearance::parse(m_formManager->getForm()->getDefaultAppearance().value_or(QByteArray())),
                           m_formManager->getForm()->getDefaultAlignment(),
                           m_formManager->getWidgetRectangle(m_formWidget),
                           parentField->getOptions(),
                           parentField->getTopIndex(),
                           getSelectedItems(parentField->getValue(), parentField->getSelection()));
}

void PDFFormFieldListBoxEditor::setFocusImpl(bool focused)
{
    if (!focused && !m_listBox.isReadonly() && !m_formManager->isCommitDisabled())
    {
        commit();
    }
}

std::set<int> PDFFormFieldListBoxEditor::getSelectedItems(PDFObject value, PDFObject indices) const
{
    std::set<int> result;

    PDFDocumentDataLoaderDecorator loader(m_formManager->getDocument());
    value = m_formManager->getDocument()->getObject(value);

    std::vector<PDFInteger> indicesVector = loader.readIntegerArray(indices);
    if (indicesVector.empty())
    {
        const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
        Q_ASSERT(parentField);

        const PDFFormFieldChoice::Options& options = parentField->getOptions();
        auto addOption = [&options, &result](const QString& optionString)
        {
            for (size_t i = 0; i < options.size(); ++i)
            {
                const PDFFormFieldChoice::Option& option = options[i];
                if (option.userString == optionString)
                {
                    result.insert(int(i));
                }
            }
        };

        if (value.isString())
        {
            addOption(loader.readTextString(value, QString()));
        }
        else if (value.isArray())
        {
            for (const QString& string : loader.readTextStringList(value))
            {
                addOption(string);
            }
        }
    }
    else
    {
        std::sort(indicesVector.begin(), indicesVector.end());
        std::copy(indicesVector.cbegin(), indicesVector.cend(), std::inserter(result, result.cend()));
    }

    return result;
}

void PDFFormFieldListBoxEditor::commit()
{
    PDFObject object;

    const std::set<int>& selection = m_listBox.getSelection();
    if (!selection.empty())
    {
        const PDFFormFieldChoice* parentField = dynamic_cast<const PDFFormFieldChoice*>(m_formWidget.getParent());
        Q_ASSERT(parentField);

        const PDFFormFieldChoice::Options& options = parentField->getOptions();
        std::set<QString> values;

        for (const int index : selection)
        {
            values.insert(options[index].userString);
        }

        if (values.size() == 1)
        {
            object = PDFObjectFactory::createTextString(*values.begin());
        }
        else
        {
            PDFObjectFactory objectFactory;
            objectFactory.beginArray();

            for (const QString& string : values)
            {
                objectFactory << string;
            }

            objectFactory.endArray();
            object = objectFactory.takeObject();
        }
    }

    if (object != m_formWidget.getParent()->getValue())
    {
        PDFFormField::SetValueParameters parameters;
        parameters.formManager = m_formManager;
        parameters.invokingWidget = m_formWidget.getWidget();
        parameters.invokingFormField = m_formWidget.getParent();
        parameters.scope = PDFFormField::SetValueParameters::Scope::User;
        parameters.value = qMove(object);
        parameters.listboxTopIndex = m_listBox.getTopItemIndex();
        std::copy(selection.cbegin(), selection.cend(), std::back_inserter(parameters.listboxChoices));
        m_formManager->setFormFieldValue(parameters);
    }
}

bool PDFWidgetFormManager::isEditorDrawEnabled(const PDFObjectReference& reference) const
{
    const PDFFormFieldWidgetEditor* editor = getEditor(getFormFieldForWidget(reference));
    return editor && editor->isEditorDrawEnabled();
}

void PDFWidgetFormManager::onDocumentReset()
{
    updateFormWidgetEditors();
}

bool PDFWidgetFormManager::isEditorDrawEnabled(const PDFFormField* formField) const
{
    const PDFFormFieldWidgetEditor* editor = getEditor(formField);
    return editor && editor->isEditorDrawEnabled();
}

void PDFWidgetFormManager::drawFormField(const PDFFormField* formField, AnnotationDrawParameters& parameters, bool edit) const
{
    const PDFFormFieldWidgetEditor* editor = getEditor(formField);
    if (editor)
    {
        editor->draw(parameters, edit);
    }
}

}   // namespace pdf