Added support for drag and drop of text on OSX, via DragAndDropContainer::shouldDropTextWhenDraggedExternally

modules/juce_gui_basics/mouse/juce_DragAndDropContainer.cpp

@@ -300,12 +300,17 @@ private:
             : files (f), canMoveFiles (canMove)
         {}
 
+        ExternalDragAndDropMessage (const String& t) : text (t), canMoveFiles() {}
+
         void messageCallback() override
         {
-            DragAndDropContainer::performExternalDragDropOfFiles (files, canMoveFiles);
+            if (text.isEmpty())
+                DragAndDropContainer::performExternalDragDropOfFiles (files, canMoveFiles);
+            else
+                DragAndDropContainer::performExternalDragDropOfText (text);
         }
 
-    private:
+        String text;
         StringArray files;
         bool canMoveFiles;
     };
@@ -318,14 +323,21 @@ private:
             {
                 hasCheckedForExternalDrag = true;
                 StringArray files;
+                String text;
                 bool canMoveFiles = false;
 
-                if (owner.shouldDropFilesWhenDraggedExternally (details, files, canMoveFiles)
-                      && files.size() > 0
-                      && ModifierKeys::getCurrentModifiersRealtime().isAnyMouseButtonDown())
+                if (ModifierKeys::getCurrentModifiersRealtime().isAnyMouseButtonDown())
                 {
-                    (new ExternalDragAndDropMessage (files, canMoveFiles))->post();
-                    deleteSelf();
+                    if (owner.shouldDropFilesWhenDraggedExternally (details, files, canMoveFiles) && ! files.isEmpty())
+                    {
+                        (new ExternalDragAndDropMessage (files, canMoveFiles))->post();
+                        deleteSelf();
+                    }
+                    else if (owner.shouldDropTextWhenDraggedExternally (details, text) && text.isNotEmpty())
+                    {
+                        (new ExternalDragAndDropMessage (text))->post();
+                        deleteSelf();
+                    }
                 }
             }
         }
@@ -500,6 +512,11 @@ bool DragAndDropContainer::shouldDropFilesWhenDraggedExternally (const DragAndDr
     return false;
 }
 
+bool DragAndDropContainer::shouldDropTextWhenDraggedExternally (const DragAndDropTarget::SourceDetails&, String&)
+{
+    return false;
+}
+
 void DragAndDropContainer::dragOperationStarted (const DragAndDropTarget::SourceDetails&)  {}
 void DragAndDropContainer::dragOperationEnded (const DragAndDropTarget::SourceDetails&)    {}
 

modules/juce_gui_basics/mouse/juce_DragAndDropContainer.h

@@ -152,10 +152,10 @@ public:
     static bool performExternalDragDropOfText (const String& text);
 
 protected:
-    /** Override this if you want to be able to perform an external drag a set of files
+    /** Override this if you want to be able to perform an external drag of a set of files
         when the user drags outside of this container component.
 
-        This method will be called when a drag operation moves outside the Juce-based window,
+        This method will be called when a drag operation moves outside the JUCE window,
         and if you want it to then perform a file drag-and-drop, add the filenames you want
         to the array passed in, and return true.
 
@@ -163,16 +163,30 @@ protected:
         @param files            on return, the filenames you want to drag
         @param canMoveFiles     on return, true if it's ok for the receiver to move the files; false if
                                 it must make a copy of them (see the performExternalDragDropOfFiles() method)
-        @see performExternalDragDropOfFiles
+        @see performExternalDragDropOfFiles, shouldDropTextWhenDraggedExternally
     */
     virtual bool shouldDropFilesWhenDraggedExternally (const DragAndDropTarget::SourceDetails& sourceDetails,
                                                        StringArray& files, bool& canMoveFiles);
 
+    /** Override this if you want to be able to perform an external drag of text
+        when the user drags outside of this container component.
+
+        This method will be called when a drag operation moves outside the JUCE window,
+        and if you want it to then perform a text drag-and-drop, copy the text you want to
+        be dragged into the argument provided and return true.
+
+        @param sourceDetails    information about the source of the drag operation
+        @param text             on return, the text you want to drag
+        @see shouldDropFilesWhenDraggedExternally
+    */
+    virtual bool shouldDropTextWhenDraggedExternally (const DragAndDropTarget::SourceDetails& sourceDetails,
+                                                      String& text);
+
     /** Subclasses can override this to be told when a drag starts. */
-    virtual void dragOperationStarted (const DragAndDropTarget::SourceDetails& sourceDetails);
+    virtual void dragOperationStarted (const DragAndDropTarget::SourceDetails&);
 
     /** Subclasses can override this to be told when a drag finishes. */
-    virtual void dragOperationEnded (const DragAndDropTarget::SourceDetails& sourceDetails);
+    virtual void dragOperationEnded (const DragAndDropTarget::SourceDetails&);
 
 private:
     //==============================================================================

modules/juce_gui_basics/native/juce_mac_Windowing.mm

@@ -142,45 +142,113 @@ int JUCE_CALLTYPE NativeMessageBox::showYesNoCancelBox (AlertWindow::AlertIconTy
 
 
 //==============================================================================
-bool DragAndDropContainer::performExternalDragDropOfFiles (const StringArray& files, const bool /*canMoveFiles*/)
+static NSRect getDragRect (NSView* view, NSEvent* event)
 {
-    if (files.size() == 0)
-        return false;
+    auto eventPos = [event locationInWindow];
+
+    return [view convertRect: NSMakeRect (eventPos.x - 16.0f, eventPos.y - 16.0f, 32.0f, 32.0f)
+                    fromView: nil];
+}
 
-    MouseInputSource* draggingSource = Desktop::getInstance().getDraggingMouseSource(0);
+NSView* getNSViewForDragEvent()
+{
+    if (auto* draggingSource = Desktop::getInstance().getDraggingMouseSource(0))
+        if (auto* sourceComp = draggingSource->getComponentUnderMouse())
+            return (NSView*) sourceComp->getWindowHandle();
+
+    jassertfalse;  // This method must be called in response to a component's mouseDown or mouseDrag event!
+    return nil;
+}
 
-    if (draggingSource == nullptr)
+struct TextDragDataProviderClass   : public ObjCClass<NSObject>
+{
+    TextDragDataProviderClass()  : ObjCClass<NSObject> ("JUCE_NSTextDragDataProvider_")
     {
-        jassertfalse;  // This method must be called in response to a component's mouseDown or mouseDrag event!
-        return false;
+        addIvar<String*> ("text");
+        addMethod (@selector (dealloc), dealloc, "v@:");
+        addMethod (@selector (pasteboard:item:provideDataForType:), provideDataForType, "v@:@@@");
+        addProtocol (@protocol (NSPasteboardItemDataProvider));
+        registerClass();
     }
 
-    Component* sourceComp = draggingSource->getComponentUnderMouse();
+    static void setText (id self, const String& text)
+    {
+        object_setInstanceVariable (self, "text", new String (text));
+    }
 
-    if (sourceComp == nullptr)
+private:
+    static void dealloc (id self, SEL)
     {
-        jassertfalse;  // This method must be called in response to a component's mouseDown or mouseDrag event!
+        delete getIvar<String*> (self, "text");
+        sendSuperclassMessage (self, @selector (dealloc));
+    }
+
+    static void provideDataForType (id self, SEL, NSPasteboard* sender, NSPasteboardItem*, NSString* type)
+    {
+        if ([type compare: NSPasteboardTypeString] == NSOrderedSame)
+            if (auto* text = getIvar<String*> (self, "text"))
+                [sender setData: [juceStringToNS (*text) dataUsingEncoding: NSUTF8StringEncoding]
+                        forType: NSPasteboardTypeString];
+    }
+};
+
+bool DragAndDropContainer::performExternalDragDropOfText (const String& text)
+{
+    if (text.isEmpty())
         return false;
+
+    if (auto* view = getNSViewForDragEvent())
+    {
+        JUCE_AUTORELEASEPOOL
+        {
+            if (auto* event = [[view window] currentEvent])
+            {
+                static TextDragDataProviderClass dataProviderClass;
+                id delegate = [dataProviderClass.createInstance() init];
+                TextDragDataProviderClass::setText (delegate, text);
+
+                auto* pasteboardItem = [[NSPasteboardItem new] autorelease];
+                [pasteboardItem setDataProvider: delegate
+                                       forTypes: [NSArray arrayWithObjects: NSPasteboardTypeString, nil]];
+
+                auto* dragItem = [[[NSDraggingItem alloc] initWithPasteboardWriter: pasteboardItem] autorelease];
+
+                NSImage* image = [[NSWorkspace sharedWorkspace] iconForFile: nsEmptyString()];
+                [dragItem setDraggingFrame: getDragRect (view, event) contents: image];
+
+                auto* draggingSession = [view beginDraggingSessionWithItems: [NSArray arrayWithObject: dragItem]
+                                                                      event: event
+                                                                     source: delegate];
+
+                draggingSession.animatesToStartingPositionsOnCancelOrFail = YES;
+                draggingSession.draggingFormation = NSDraggingFormationNone;
+                return true;
+            }
+        }
     }
 
-    JUCE_AUTORELEASEPOOL
+    return false;
+}
+
+bool DragAndDropContainer::performExternalDragDropOfFiles (const StringArray& files, bool /*canMoveFiles*/)
+{
+    if (files.isEmpty())
+        return false;
+
+    if (auto* view = getNSViewForDragEvent())
     {
-        if (NSView* view = (NSView*) sourceComp->getWindowHandle())
+        JUCE_AUTORELEASEPOOL
         {
-            if (NSEvent* event = [[view window] currentEvent])
+            if (auto* event = [[view window] currentEvent])
             {
-                NSPoint eventPos = [event locationInWindow];
-                NSRect dragRect = [view convertRect: NSMakeRect (eventPos.x - 16.0f, eventPos.y - 16.0f, 32.0f, 32.0f)
-                                           fromView: nil];
+                auto dragRect = getDragRect (view, event);
 
                 for (int i = 0; i < files.size(); ++i)
-                {
                     if (! [view dragFile: juceStringToNS (files[i])
                                 fromRect: dragRect
                                slideBack: YES
                                    event: event])
                         return false;
-                }
 
                 return true;
             }
@@ -190,12 +258,6 @@ bool DragAndDropContainer::performExternalDragDropOfFiles (const StringArray& fi
     return false;
 }
 
-bool DragAndDropContainer::performExternalDragDropOfText (const String& /*text*/)
-{
-    jassertfalse;    // not implemented!
-    return false;
-}
-
 //==============================================================================
 bool Desktop::canUseSemiTransparentWindows() noexcept
 {
@@ -206,8 +268,8 @@ Point<float> MouseInputSource::getCurrentRawMousePosition()
 {
     JUCE_AUTORELEASEPOOL
     {
-        const NSPoint p ([NSEvent mouseLocation]);
-        return Point<float> ((float) p.x, (float) (getMainScreenHeight() - p.y));
+        auto p = [NSEvent mouseLocation];
+        return { (float) p.x, (float) (getMainScreenHeight() - p.y) };
     }
 }