linux implementation of juce_areThereAnyAlwaysOnTopWindows()

modules/juce_gui_basics/native/juce_linux_Windowing.cpp

@@ -792,6 +792,14 @@ static void* createDraggingHandCursor()
     return CustomMouseCursorInfo (ImageFileFormat::loadFrom (dragHandData, dragHandDataSize), 8, 7).create();
 }
 
+//==============================================================================
+static int numAlwaysOnTopPeers = 0;
+
+bool juce_areThereAnyAlwaysOnTopWindows()
+{
+    return numAlwaysOnTopPeers > 0;
+}
+
 //==============================================================================
 class LinuxComponentPeer  : public ComponentPeer
 {
@@ -800,7 +808,8 @@ public:
         : ComponentPeer (comp, windowStyleFlags),
           windowH (0), parentWindow (0),
           fullScreen (false), mapped (false),
-          visual (nullptr), depth (0)
+          visual (nullptr), depth (0),
+          isAlwaysOnTop (comp.isAlwaysOnTop())
     {
         // it's dangerous to create a window on a thread other than the message thread..
         jassert (MessageManager::getInstance()->currentThreadHasLockedMessageManager());
@@ -808,6 +817,9 @@ public:
         dispatchWindowMessage = windowMessageReceive;
         repainter = new LinuxRepaintManager (*this);
 
+        if (isAlwaysOnTop)
+            ++numAlwaysOnTopPeers;
+
         createWindow (parentToAddTo);
 
         setTitle (component.getName());
@@ -821,6 +833,9 @@ public:
         deleteIconPixmaps();
         destroyWindow();
         windowH = 0;
+
+        if (isAlwaysOnTop)
+            --numAlwaysOnTopPeers;
     }
 
     // (this callback is hooked up in the messaging code)
@@ -1915,6 +1930,7 @@ private:
     Visual* visual;
     int depth;
     BorderSize<int> windowBorder;
+    bool isAlwaysOnTop;
     enum { KeyPressEventType = 2 };
 
     struct MotifWmHints
@@ -3139,12 +3155,6 @@ bool Desktop::isScreenSaverEnabled()
     return screenSaverAllowed;
 }
 
-//==============================================================================
-bool juce_areThereAnyAlwaysOnTopWindows()
-{
-    return false; // XXX should be implemented
-}
-
 //==============================================================================
 void* CustomMouseCursorInfo::create() const
 {