UIViewComponentPeer: Enable non-full-screen views

modules/juce_gui_basics/native/juce_ios_Windowing.mm

@@ -661,6 +661,20 @@ Desktop::DisplayOrientation Desktop::getCurrentOrientation() const
     return Orientations::convertToJuce (orientation);
 }
 
+static Rectangle<int> getRecommendedWindowBounds()
+{
+    // The most straightforward way of retrieving the screen area available to an iOS app
+    // seems to be to create a new window (which will take up all available space) and to
+    // query its frame.
+    struct TemporaryWindow
+    {
+        UIWindow* window = [[UIWindow alloc] init];
+        ~TemporaryWindow() noexcept { [window release]; }
+    };
+
+    return convertToRectInt (TemporaryWindow{}.window.frame);
+}
+
 void Displays::findDisplays (float masterScale)
 {
     JUCE_AUTORELEASEPOOL
@@ -668,7 +682,8 @@ void Displays::findDisplays (float masterScale)
         UIScreen* s = [UIScreen mainScreen];
 
         Display d;
-        d.userArea = d.totalArea = convertToRectInt ([s bounds]) / masterScale;
+        d.totalArea = convertToRectInt ([s bounds]) / masterScale;
+        d.userArea = getRecommendedWindowBounds() / masterScale;
         d.isMain = true;
         d.scale = masterScale * s.scale;
         d.dpi = 160 * d.scale;