Optimize usage of QPalette

setPalette() does not replace the old one but rather adds the
difference. Thus a previous copy of the palette is unnecessary.

Change-Id: I5c06da456b76144efc4a984ccda13c7d2243a7bc
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/libs/qmleditorwidgets/customcolordialog.cpp

@@ -144,7 +144,7 @@ CustomColorDialog::CustomColorDialog(QWidget *parent) : QFrame(parent )
 
 void CustomColorDialog::setupColor(const QColor &color)
 {
-    QPalette pal = m_beforeColorWidget->palette();
+    QPalette pal;
     pal.setColor(QPalette::Background, color);
     m_beforeColorWidget->setPalette(pal);
     setColor(color);
@@ -179,7 +179,7 @@ void CustomColorDialog::setupWidgets()
     m_gSpinBox->setValue(m_color.greenF());
     m_bSpinBox->setValue(m_color.blueF());
     m_colorBox->setColor(m_color);
-    QPalette pal = m_currentColorWidget->palette();
+    QPalette pal;
     pal.setColor(QPalette::Background, m_color);
     m_currentColorWidget->setPalette(pal);
     m_blockUpdate = false;

src/plugins/coreplugin/fancytabwidget.cpp

@@ -451,11 +451,9 @@ void FancyTabWidget::removeTab(int index)
 
 void FancyTabWidget::setBackgroundBrush(const QBrush &brush)
 {
-    QPalette pal = m_tabBar->palette();
+    QPalette pal;
     pal.setBrush(QPalette::Mid, brush);
     m_tabBar->setPalette(pal);
-    pal = m_cornerWidgetContainer->palette();
-    pal.setBrush(QPalette::Mid, brush);
     m_cornerWidgetContainer->setPalette(pal);
 }
 

src/plugins/coreplugin/find/searchresulttreeview.cpp

@@ -62,7 +62,7 @@ void SearchResultTreeView::setTextEditorFont(const QFont &font, const SearchResu
 {
     m_model->setTextEditorFont(font, color);
 
-    QPalette p = palette();
+    QPalette p;
     p.setColor(QPalette::Base, color.textBackground);
     setPalette(p);
 }

src/plugins/coreplugin/find/searchresultwidget.cpp

@@ -90,7 +90,7 @@ SearchResultWidget::SearchResultWidget(QWidget *parent) :
     setLayout(layout);
 
     QFrame *topWidget = new QFrame;
-    QPalette pal = topWidget->palette();
+    QPalette pal;
     pal.setColor(QPalette::Window, QColor(255, 255, 225));
     pal.setColor(QPalette::WindowText, Qt::black);
     topWidget->setPalette(pal);
@@ -103,7 +103,6 @@ SearchResultWidget::SearchResultWidget(QWidget *parent) :
     layout->addWidget(topWidget);
 
     m_messageWidget = new QFrame;
-    pal.setColor(QPalette::Window, QColor(255, 255, 225));
     pal.setColor(QPalette::WindowText, Qt::red);
     m_messageWidget->setPalette(pal);
     m_messageWidget->setFrameStyle(QFrame::Panel | QFrame::Raised);

src/plugins/coreplugin/infobar.cpp

@@ -207,7 +207,7 @@ void InfoBarDisplay::update()
     foreach (const InfoBarEntry &info, m_infoBar->m_infoBarEntries) {
         QFrame *infoWidget = new QFrame;
 
-        QPalette pal = infoWidget->palette();
+        QPalette pal;
         pal.setColor(QPalette::Window, QColor(255, 255, 225));
         pal.setColor(QPalette::WindowText, Qt::black);
 

src/plugins/git/changeselectiondialog.cpp

@@ -177,7 +177,7 @@ void ChangeSelectionDialog::acceptShow()
 //! Set commit message in details
 void ChangeSelectionDialog::setDetails(int exitCode)
 {
-    QPalette palette = m_ui->changeNumberEdit->palette();
+    QPalette palette;
     if (exitCode == 0) {
         m_ui->detailsText->setPlainText(QString::fromUtf8(m_process->readAllStandardOutput()));
         palette.setColor(QPalette::Text, Qt::black);

src/plugins/git/gerrit/gerritdialog.cpp

@@ -68,7 +68,7 @@ QueryValidatingLineEdit::QueryValidatingLineEdit(QWidget *parent)
 
 void QueryValidatingLineEdit::setTextColor(const QColor &c)
 {
-    QPalette pal = palette();
+    QPalette pal;
     pal.setColor(QPalette::Active, QPalette::Text, c);
     setPalette(pal);
 }

src/plugins/projectexplorer/miniprojecttargetselector.cpp

@@ -648,7 +648,7 @@ MiniProjectTargetSelector::MiniProjectTargetSelector(QAction *targetSelectorActi
     m_runConfiguration(0),
     m_hideOnRelease(false)
 {
-    QPalette p = palette();
+    QPalette p;
     p.setColor(QPalette::Text, QColor(255, 255, 255, 160));
     setPalette(p);
     setProperty("panelwidget", true);

src/plugins/projectexplorer/projectwindow.cpp

@@ -123,7 +123,7 @@ PanelsWidget::PanelsWidget(QWidget *parent) :
     m_root->setMaximumWidth(900);
     m_root->setContentsMargins(0, 0, 40, 0);
 
-    QPalette pal = m_root->palette();
+    QPalette pal;
     QColor background = Utils::StyleHelper::mergedColors(
                 palette().window().color(), Qt::white, 85);
     pal.setColor(QPalette::All, QPalette::Window, background.darker(102));

src/plugins/projectexplorer/targetsettingswidget.cpp

@@ -69,7 +69,7 @@ TargetSettingsWidget::TargetSettingsWidget(QWidget *parent) :
     connect(m_targetSelector, SIGNAL(menuShown(int)),
             this, SIGNAL(menuShown(int)));
 
-    QPalette shadowPal = palette();
+    QPalette shadowPal;
     QLinearGradient grad(0, 0, 0, 2);
     grad.setColorAt(0, QColor(0, 0, 0, 60));
     grad.setColorAt(1, Qt::transparent);

src/plugins/qmlprofiler/qmlprofilertool.cpp

@@ -267,7 +267,7 @@ QWidget *QmlProfilerTool::createWidgets()
     layout->addWidget(d->m_clearButton);
 
     d->m_timeLabel = new QLabel();
-    QPalette palette = d->m_timeLabel->palette();
+    QPalette palette;
     palette.setColor(QPalette::WindowText, Qt::white);
     d->m_timeLabel->setPalette(palette);
     d->m_timeLabel->setIndent(10);

src/plugins/texteditor/basetexteditor.cpp

@@ -5394,7 +5394,7 @@ void BaseTextEditorWidget::applyFontSettings()
     updateTabStops(); // update tab stops, they depend on the font
 
     // Line numbers
-    QPalette ep = d->m_extraArea->palette();
+    QPalette ep;
     ep.setColor(QPalette::Dark, lineNumberFormat.foreground().color());
     ep.setColor(QPalette::Background, lineNumberFormat.background().style() != Qt::NoBrush ?
                 lineNumberFormat.background().color() : background);

src/plugins/texteditor/colorschemeedit.cpp

@@ -329,7 +329,7 @@ void ColorSchemeEdit::checkCheckBoxes()
 
 void ColorSchemeEdit::setItemListBackground(const QColor &color)
 {
-    QPalette pal = m_ui->itemList->palette();
+    QPalette pal;
     pal.setColor(QPalette::Base, color);
     m_ui->itemList->setPalette(pal);
 }

src/plugins/vcsbase/checkoutprogresswizardpage.cpp

@@ -99,7 +99,7 @@ void CheckoutProgressWizardPage::slotFinished(bool ok, int exitCode, const QVari
             m_state = Succeeded;
             QApplication::restoreOverrideCursor();
             ui->statusLabel->setText(tr("Succeeded."));
-            QPalette palette = ui->statusLabel->palette();
+            QPalette palette;
             palette.setColor(QPalette::Active, QPalette::Text, Qt::green);
             ui->statusLabel->setPalette(palette);
             emit completeChanged();
@@ -111,7 +111,7 @@ void CheckoutProgressWizardPage::slotFinished(bool ok, int exitCode, const QVari
             m_state = Failed;
             QApplication::restoreOverrideCursor();
             ui->statusLabel->setText(tr("Failed."));
-            QPalette palette = ui->statusLabel->palette();
+            QPalette palette;
             palette.setColor(QPalette::Active, QPalette::Text, Qt::red);
             ui->statusLabel->setPalette(palette);
             emit terminated(false);

src/plugins/vcsbase/vcsbasesubmiteditor.cpp

@@ -191,7 +191,7 @@ VcsBaseSubmitEditor::VcsBaseSubmitEditor(const VcsBaseSubmitEditorParameters *pa
     const QTextCharFormat tf = fs.toTextCharFormat(TextEditor::C_TEXT);
     descriptionEdit->setFont(tf.font());
     const QTextCharFormat selectionFormat = fs.toTextCharFormat(TextEditor::C_SELECTION);
-    QPalette pal = descriptionEdit->palette();
+    QPalette pal;
     pal.setColor(QPalette::Base, tf.background().color());
     pal.setColor(QPalette::Text, tf.foreground().color());
     pal.setColor(QPalette::Foreground, tf.foreground().color());