Added option to disable playlist clear button

Fixes #339

src/core/mainwindow.cpp

@@ -949,6 +949,7 @@ void MainWindow::ReloadAllSettings() {
   osd_->ReloadSettings();
   collection_view_->ReloadSettings();
   ui_->playlist->view()->ReloadSettings();
+  app_->playlist_manager()->playlist_container()->ReloadSettings();
   app_->album_cover_loader()->ReloadSettings();
   album_cover_choice_controller_->ReloadSettings();
   if (cover_manager_.get()) cover_manager_->ReloadSettings();

src/playlist/playlistcontainer.cpp

@@ -118,6 +118,8 @@ PlaylistContainer::PlaylistContainer(QWidget *parent)
   connect(ui_->playlist, SIGNAL(FocusOnFilterSignal(QKeyEvent*)), SLOT(FocusOnFilter(QKeyEvent*)));
   ui_->filter->installEventFilter(this);
 
+  ReloadSettings();
+
 }
 
 PlaylistContainer::~PlaylistContainer() { delete ui_; }
@@ -225,6 +227,18 @@ void PlaylistContainer::SetViewModel(Playlist *playlist) {
 
 }
 
+void PlaylistContainer::ReloadSettings() {
+
+  bool playlist_clear = settings_.value("playlist_clear", true).toBool();
+  if (playlist_clear) {
+    ui_->clear->show();
+  }
+  else {
+    ui_->clear->hide();
+  }
+
+}
+
 void PlaylistContainer::ActivePlaying() {
   UpdateActiveIcon(QIcon(":/pictures/tiny-play.png"));
 }

src/playlist/playlistcontainer.h

@@ -56,6 +56,7 @@ class PlaylistContainer : public QWidget {
 
   void SetActions(QAction *new_playlist, QAction *load_playlist, QAction *save_playlist, QAction *clear_playlist, QAction *next_playlist, QAction *previous_playlist);
   void SetManager(PlaylistManager *manager);
+  void ReloadSettings();
 
   PlaylistView *view() const;
 

src/settings/playlistsettingspage.cpp

@@ -66,6 +66,7 @@ void PlaylistSettingsPage::Load() {
   ui_->checkbox_greyout_songs_startup->setChecked(s.value("greyout_songs_startup", true).toBool());
   ui_->checkbox_greyout_songs_play->setChecked(s.value("greyout_songs_play", true).toBool());
   ui_->checkbox_select_track->setChecked(s.value("select_track", false).toBool());
+  ui_->checkbox_playlist_clear->setChecked(s.value("playlist_clear", true).toBool());
 
   Playlist::Path path = Playlist::Path(s.value(Playlist::kPathType, Playlist::Path_Automatic).toInt());
   switch (path) {
@@ -114,6 +115,7 @@ void PlaylistSettingsPage::Save() {
   s.setValue("greyout_songs_startup", ui_->checkbox_greyout_songs_startup->isChecked());
   s.setValue("greyout_songs_play", ui_->checkbox_greyout_songs_play->isChecked());
   s.setValue("select_track", ui_->checkbox_select_track->isChecked());
+  s.setValue("playlist_clear", ui_->checkbox_playlist_clear->isChecked());
   s.setValue(Playlist::kPathType, static_cast<int>(path));
   s.setValue("editmetadatainline", ui_->checkbox_editmetadatainline->isChecked());
   s.setValue(Playlist::kWriteMetadata, ui_->checkbox_writemetadata->isChecked());

src/settings/playlistsettingspage.ui

@@ -56,6 +56,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QCheckBox" name="checkbox_playlist_clear">
+     <property name="text">
+      <string>Enable playlist clear button</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QGroupBox" name="groupbox_paths">
      <property name="title">