Make the colours in the stylesheet obey the Qt colour scheme.

Fixes issue #37

data/mainwindow.css

@@ -1,5 +1,5 @@
 #playlist {
-  background-color: white;
+  background-color: %palette-base;
   background-image: url(:logo.png);
   background-attachment: fixed;
   background-position: bottom right;
@@ -22,8 +22,8 @@ QToolButton[popupMode="1"] {
 }
 
 QToolButton:hover {
-  border: 2px solid #fec798;
-  background-color: #fedbbd;
+  border: 2px solid %palette-highlight;
+  background-color: %palette-highlight-lighter;
   border-radius: 3px;
   padding: 1px;
 }
@@ -33,8 +33,8 @@ QToolButton:hover[popupMode="1"] {
 }
 
 QToolButton:pressed {
-  border: 2px solid #fe963e;
-  background-color: #fedbbd;
+  border: 2px solid %palette-highlight-darker;
+  background-color: %palette-highlight-lighter;
   border-radius: 3px;
   padding: 1px;
 }

src/mainwindow.cpp

@@ -16,6 +16,7 @@
 #include "libraryconfigdialog.h"
 #include "about.h"
 #include "addstreamdialog.h"
+#include "stylesheetloader.h"
 
 #include "qxtglobalshortcut.h"
 
@@ -263,12 +264,8 @@ MainWindow::MainWindow(QWidget *parent)
   multi_loading_indicator_->hide();
 
   // Load theme
-  QFile stylesheet(":mainwindow.css");
-  if (!stylesheet.open(QIODevice::ReadOnly)) {
-    qWarning("Could not open stylesheet");
-  } else {
-    setStyleSheet(stylesheet.readAll());
-  }
+  StyleSheetLoader* css_loader = new StyleSheetLoader(this);
+  css_loader->SetStyleSheet(this, ":mainwindow.css");
 
   // Load settings
   settings.beginGroup(kSettingsGroup);

src/src.pro

@@ -54,7 +54,8 @@ SOURCES += main.cpp \
     about.cpp \
     albumcoverfetcher.cpp \
     addstreamdialog.cpp \
-    savedradio.cpp
+    savedradio.cpp \
+    stylesheetloader.cpp
 HEADERS += mainwindow.h \
     player.h \
     library.h \
@@ -109,7 +110,8 @@ HEADERS += mainwindow.h \
     about.h \
     albumcoverfetcher.h \
     addstreamdialog.h \
-    savedradio.h
+    savedradio.h \
+    stylesheetloader.h
 FORMS += mainwindow.ui \
     libraryconfig.ui \
     fileview.ui \
@@ -178,9 +180,9 @@ win32|fedora-win32-cross:LIBS += -ltag \
     -lpthreadGC2
 
 # OSD
-unix:!macx {
+unix:!macx { 
     SOURCES += osd_x11.cpp
-    !nolibnotify {
+    !nolibnotify { 
         DEFINES += HAVE_LIBNOTIFY
         QMAKE_CXXFLAGS += $$system(pkg-config --cflags libnotify)
         LIBS += $$system(pkg-config --libs libnotify)

src/stylesheetloader.cpp

@@ -0,0 +1,77 @@
+#include "stylesheetloader.h"
+
+#include <QtDebug>
+#include <QFile>
+#include <QEvent>
+
+StyleSheetLoader::StyleSheetLoader(QObject* parent)
+  : QObject(parent)
+{
+}
+
+void StyleSheetLoader::SetStyleSheet(QWidget* widget, const QString &filename) {
+  filenames_[widget] = filename;
+  widget->installEventFilter(this);
+  UpdateStyleSheet(widget);
+}
+
+void StyleSheetLoader::UpdateStyleSheet(QWidget *widget) {
+  QString filename(filenames_[widget]);
+
+  // Load the file
+  QFile file(filename);
+  if (!file.open(QIODevice::ReadOnly)) {
+    qWarning() << __PRETTY_FUNCTION__ << "error opening" << filename;
+    return;
+  }
+  QString contents(file.readAll());
+
+  // Replace %palette-role with actual colours
+  QPalette p(widget->palette());
+  ReplaceColor(&contents, "Window", p, QPalette::Window);
+  ReplaceColor(&contents, "Background", p, QPalette::Background);
+  ReplaceColor(&contents, "WindowText", p, QPalette::WindowText);
+  ReplaceColor(&contents, "Foreground", p, QPalette::Foreground);
+  ReplaceColor(&contents, "Base", p, QPalette::Base);
+  ReplaceColor(&contents, "AlternateBase", p, QPalette::AlternateBase);
+  ReplaceColor(&contents, "ToolTipBase", p, QPalette::ToolTipBase);
+  ReplaceColor(&contents, "ToolTipText", p, QPalette::ToolTipText);
+  ReplaceColor(&contents, "Text", p, QPalette::Text);
+  ReplaceColor(&contents, "Button", p, QPalette::Button);
+  ReplaceColor(&contents, "ButtonText", p, QPalette::ButtonText);
+  ReplaceColor(&contents, "BrightText", p, QPalette::BrightText);
+  ReplaceColor(&contents, "Light", p, QPalette::Light);
+  ReplaceColor(&contents, "Midlight", p, QPalette::Midlight);
+  ReplaceColor(&contents, "Dark", p, QPalette::Dark);
+  ReplaceColor(&contents, "Mid", p, QPalette::Mid);
+  ReplaceColor(&contents, "Shadow", p, QPalette::Shadow);
+  ReplaceColor(&contents, "Highlight", p, QPalette::Highlight);
+  ReplaceColor(&contents, "HighlightedText", p, QPalette::HighlightedText);
+  ReplaceColor(&contents, "Link", p, QPalette::Link);
+  ReplaceColor(&contents, "LinkVisited", p, QPalette::LinkVisited);
+
+  widget->setStyleSheet(contents);
+}
+
+void StyleSheetLoader::ReplaceColor(QString* css, const QString& name,
+                                    const QPalette& palette,
+                                    QPalette::ColorRole role) const {
+  css->replace("%palette-" + name + "-lighter",
+               palette.color(role).lighter().name(), Qt::CaseInsensitive);
+  css->replace("%palette-" + name + "-darker",
+               palette.color(role).darker().name(), Qt::CaseInsensitive);
+  css->replace("%palette-" + name,
+               palette.color(role).name(), Qt::CaseInsensitive);
+}
+
+bool StyleSheetLoader::eventFilter(QObject* obj, QEvent* event) {
+  if (event->type() != QEvent::PaletteChange)
+    return false;
+
+  QWidget* widget = qobject_cast<QWidget*>(obj);
+  if (!widget || !filenames_.contains(widget))
+    return false;
+
+  UpdateStyleSheet(widget);
+  return false;
+}

src/stylesheetloader.h

@@ -0,0 +1,31 @@
+#ifndef STYLESHEETLOADER_H
+#define STYLESHEETLOADER_H
+
+#include <QString>
+#include <QPalette>
+#include <QWidget>
+#include <QMap>
+
+class StyleSheetLoader : public QObject {
+ public:
+  StyleSheetLoader(QObject* parent = 0);
+
+  // Sets the given stylesheet on the given widget.
+  // If the stylesheet contains strings like %palette-[role], these get replaced
+  // with actual palette colours.
+  // The stylesheet is reloaded when the widget's palette changes.
+  void SetStyleSheet(QWidget* widget, const QString& filename);
+
+ protected:
+  bool eventFilter(QObject* obj, QEvent* event);
+
+ private:
+  void UpdateStyleSheet(QWidget* widget);
+  void ReplaceColor(QString* css, const QString& name, const QPalette& palette,
+                    QPalette::ColorRole role) const;
+
+ private:
+  QMap<QWidget*, QString> filenames_;
+};
+
+#endif // STYLESHEETLOADER_H