Add 2x icons for retina displays.

This change updates the mode selector/fancyactionbar
in Qt Creator with new high-resolution icons.

Set Qt::AA_UseHighDpiImages on Qt 5.1 and higher to
make QIcon generate high-dpi pixmaps. Add "@2x" mode
images.

Update StyleHelper::drawIconWithShadow to handle high-dpi
pixmaps. The shadow-drawing algorithm is kept in device
pixels.

Change-Id: I411b7a24e534a2d75a1bbdc4d10219dcbea26bed
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

src/app/main.cpp

@@ -307,6 +307,10 @@ int main(int argc, char **argv)
     QtSystemExceptionHandler systemExceptionHandler;
 #endif
 
+#if QT_VERSION >= 0x050100
+    app.setAttribute(Qt::AA_UseHighDpiPixmaps);
+#endif
+
     // Manually determine -settingspath command line option
     // We can't use the regular way of the plugin manager, because that needs to parse pluginspecs
     // but the settings path can influence which plugins are enabled

src/libs/utils/stylehelper.cpp

@@ -35,6 +35,7 @@
 #include <QPainter>
 #include <QApplication>
 #include <QStyleOption>
+#include <qmath.h>
 
 // Clamps float color values within (0, 255)
 static int clamp(float x)
@@ -363,15 +364,32 @@ void StyleHelper::menuGradient(QPainter *painter, const QRect &spanRect, const Q
     }
 }
 
+static qreal pixmapDevicePixelRatio(const QPixmap &pixmap)
+{
+#if QT_VERSION > 0x050000
+    return pixmap.devicePixelRatio();
+#else
+    return 1.0;
+#endif
+}
+
 // Draws a cached pixmap with shadow
 void StyleHelper::drawIconWithShadow(const QIcon &icon, const QRect &rect,
-                                     QPainter *p, QIcon::Mode iconMode, int radius, const QColor &color, const QPoint &offset)
+                                     QPainter *p, QIcon::Mode iconMode, int dipRadius, const QColor &color, const QPoint &dipOffset)
 {
     QPixmap cache;
     QString pixmapName = QString::fromLatin1("icon %0 %1 %2").arg(icon.cacheKey()).arg(iconMode).arg(rect.height());
 
     if (!QPixmapCache::find(pixmapName, cache)) {
+        // High-dpi support: The in parameters (rect, radius, offset) are in
+        // device-independent pixels. The call to QIcon::pixmap() below might
+        // return a high-dpi pixmap, which will in that case have a devicePixelRatio
+        // different than 1. The shadow drawing caluculations are done in device
+        // pixels.
         QPixmap px = icon.pixmap(rect.size());
+        int devicePixelRatio = qCeil(pixmapDevicePixelRatio(px));
+        int radius = dipRadius * devicePixelRatio;
+        QPoint offset = dipOffset * devicePixelRatio;
         cache = QPixmap(px.size() + QSize(radius * 2, radius * 2));
         cache.fill(Qt::transparent);
 
@@ -396,7 +414,7 @@ void StyleHelper::drawIconWithShadow(const QIcon &icon, const QRect &rect,
 
         QPainter tmpPainter(&tmp);
         tmpPainter.setCompositionMode(QPainter::CompositionMode_Source);
-        tmpPainter.drawPixmap(QPoint(radius, radius), px);
+        tmpPainter.drawPixmap(QRect(radius, radius, px.width(), px.height()), px);
         tmpPainter.end();
 
         // blur the alpha channel
@@ -423,13 +441,17 @@ void StyleHelper::drawIconWithShadow(const QIcon &icon, const QRect &rect,
         cachePainter.drawImage(QRect(0, 0, cache.rect().width(), cache.rect().height()), tmp);
 
         // Draw the actual pixmap...
-        cachePainter.drawPixmap(QPoint(radius, radius) + offset, px);
+        cachePainter.drawPixmap(QRect(QPoint(radius, radius) + offset, QSize(px.width(), px.height())), px);
+#if QT_VERSION > 0x050000
+        cache.setDevicePixelRatio(devicePixelRatio);
+#endif
         QPixmapCache::insert(pixmapName, cache);
     }
 
     QRect targetRect = cache.rect();
-    targetRect.moveCenter(rect.center());
-    p->drawPixmap(targetRect.topLeft() - offset, cache);
+    targetRect.setSize(targetRect.size() / pixmapDevicePixelRatio(cache));
+    targetRect.moveCenter(rect.center() - dipOffset);
+    p->drawPixmap(targetRect, cache);
 }
 
 // Draws a CSS-like border image where the defined borders are not stretched

src/libs/utils/stylehelper.h

@@ -83,8 +83,8 @@ public:
     static bool usePixmapCache() { return true; }
 
     static void drawIconWithShadow(const QIcon &icon, const QRect &rect, QPainter *p, QIcon::Mode iconMode,
-                                   int radius = 3, const QColor &color = QColor(0, 0, 0, 130),
-                                   const QPoint &offset = QPoint(1, -2));
+                                   int dipRadius = 3, const QColor &color = QColor(0, 0, 0, 130),
+                                   const QPoint &dipOffset = QPoint(1, -2));
     static void drawCornerImage(const QImage &img, QPainter *painter, QRect rect,
                          int left = 0, int top = 0, int right = 0, int bottom = 0);
 

src/plugins/analyzerbase/analyzerbase.qrc

@@ -1,6 +1,7 @@
 <RCC>
     <qresource prefix="/">
         <file>images/analyzer_mode.png</file>
+        <file>images/analyzer_mode@2x.png</file>
         <file>images/analyzer_category.png</file>
         <file>images/analyzer_start_small.png</file>
     </qresource>

src/plugins/coreplugin/coreconstants.h

@@ -204,6 +204,7 @@ const char ICON_CLOSE_SPLIT_RIGHT[]  = ":/core/images/splitbutton_closeright.png
 const char ICON_FILTER[]             = ":/core/images/filtericon.png";
 const char ICON_LINK[]               = ":/core/images/linkicon.png";
 const char ICON_QTLOGO_32[]          = ":/core/images/logo/32/QtProject-qtcreator.png";
+const char ICON_QTLOGO_64[]          = ":/core/images/logo/64/QtProject-qtcreator.png";
 const char ICON_QTLOGO_128[]         = ":/core/images/logo/128/QtProject-qtcreator.png";
 
 const char WIZARD_CATEGORY_QT[] = "R.Qt";

src/plugins/coreplugin/fancyactionbar.qrc

@@ -1,10 +1,15 @@
 <RCC>
     <qresource prefix="/fancyactionbar">
         <file>images/mode_Debug.png</file>
+        <file>images/mode_Debug@2x.png</file>
         <file>images/mode_Edit.png</file>
+        <file>images/mode_Edit@2x.png</file>
         <file>images/mode_Output.png</file>
         <file>images/mode_Project.png</file>
+        <file>images/mode_Project@2x.png</file>
         <file>images/mode_Reference.png</file>
+        <file>images/mode_Reference@2x.png</file>
         <file>images/mode_Design.png</file>
+        <file>images/mode_Design@2x.png</file>
     </qresource>
 </RCC>

src/plugins/welcome/welcomeplugin.cpp

@@ -136,7 +136,11 @@ WelcomeMode::WelcomeMode() :
     , m_networkAccessManagerFactory(new NetworkAccessManagerFactory)
 {
     setDisplayName(tr("Welcome"));
-    setIcon(QIcon(QLatin1String(Core::Constants::ICON_QTLOGO_32)));
+    QIcon qtLogo;
+    qtLogo.addFile(QLatin1String(Core::Constants::ICON_QTLOGO_32));
+    qtLogo.addFile(QLatin1String(Core::Constants::ICON_QTLOGO_64));
+    qtLogo.addFile(QLatin1String(Core::Constants::ICON_QTLOGO_128));
+    setIcon(qtLogo);
     setPriority(Core::Constants::P_MODE_WELCOME);
     setId(Core::Constants::MODE_WELCOME);
     setType(Core::Constants::MODE_WELCOME_TYPE);