Merge pull request #1067 from iPlug2/graphics/external-drag

Add IGraphics::InitiateExternalFileDragDrop()
iPlug2 · Mar 16, 2024 · 759d9fd · 759d9fd
2 parents 876c85a + c412910
commit 759d9fd
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Showing 8 changed files with 377 additions and 1 deletion.
diff --git a/IGraphics/IGraphics.h b/IGraphics/IGraphics.h
@@ -865,6 +865,12 @@ class IGraphics
    * @return /c true on success */
   virtual bool SetFilePathInClipboard(const char* path) { return false; }
 
+  /** Initiate an drag-n-drop operation of an existing file, to be dropped outside of the current window
+   * @param path A CString that contains a path to a file on disk
+   * @param iconBounds The area where the icon should appear
+   * @return /c true on success */
+  virtual bool InitiateExternalFileDragDrop(const char* path, const IRECT& iconBounds) { return false; };
+
   /** Call this if you modify control tool tips at runtime. \todo explain */
   virtual void UpdateTooltips() = 0;
 

diff --git a/IGraphics/Platforms/IGraphicsMac.h b/IGraphics/Platforms/IGraphicsMac.h
@@ -69,6 +69,8 @@ class IGraphicsMac final : public IGRAPHICS_DRAW_CLASS
   bool SetTextInClipboard(const char* str) override;
   bool SetFilePathInClipboard(const char* path) override;
 
+  bool InitiateExternalFileDragDrop(const char* path, const IRECT& iconBounds) override API_AVAILABLE(macos(10.13));
+
   float MeasureText(const IText& text, const char* str, IRECT& bounds) const override;
 
   EUIAppearance GetUIAppearance() const override;

diff --git a/IGraphics/Platforms/IGraphicsMac.mm b/IGraphics/Platforms/IGraphicsMac.mm
@@ -662,6 +662,28 @@ static int GetSystemVersion()
   return (bool)success;
 }
 
+bool IGraphicsMac::InitiateExternalFileDragDrop(const char* path, const IRECT& iconBounds)
+{
+  NSPasteboardItem* pasteboardItem = [[NSPasteboardItem alloc] init];
+  NSURL* fileURL = [NSURL fileURLWithPath: [NSString stringWithUTF8String: path]];
+  [pasteboardItem setString:fileURL.absoluteString forType:NSPasteboardTypeFileURL];
+
+  NSDraggingItem* draggingItem = [[NSDraggingItem alloc] initWithPasteboardWriter:pasteboardItem];
+  NSRect draggingFrame = ToNSRect(this, iconBounds);
+  NSImage* iconImage = [[NSWorkspace sharedWorkspace] iconForFile:fileURL.path];
+  [iconImage setSize:NSMakeSize(64, 64)];
+  [draggingItem setDraggingFrame:draggingFrame contents: iconImage];
+
+  IGRAPHICS_VIEW* view = (IGRAPHICS_VIEW*) mView;
+  NSDraggingSession* draggingSession = [view beginDraggingSessionWithItems:@[draggingItem] event:[NSApp currentEvent] source: view];
+  draggingSession.animatesToStartingPositionsOnCancelOrFail = YES;
+  draggingSession.draggingFormation = NSDraggingFormationNone;
+
+  ReleaseMouseCapture();
+
+  return true;
+}
+
 EUIAppearance IGraphicsMac::GetUIAppearance() const
 {
   if (@available(macOS 10.14, *)) {

diff --git a/IGraphics/Platforms/IGraphicsMac_view.h b/IGraphics/Platforms/IGraphicsMac_view.h
@@ -113,7 +113,7 @@ using namespace igraphics;
 #define VIEW_BASE NSView
 #endif
 
-@interface IGRAPHICS_VIEW : VIEW_BASE <NSTextFieldDelegate/*, WKScriptMessageHandler*/>
+@interface IGRAPHICS_VIEW : VIEW_BASE <NSTextFieldDelegate, NSDraggingSource/*, WKScriptMessageHandler*/>
 {
   CVDisplayLinkRef mDisplayLink;
   dispatch_source_t mDisplaySource;
@@ -174,6 +174,7 @@ using namespace igraphics;
 //drag-and-drop
 - (NSDragOperation) draggingEntered: (id <NSDraggingInfo>) sender;
 - (BOOL) performDragOperation: (id<NSDraggingInfo>) sender;
+- (NSDragOperation)draggingSession:(NSDraggingSession*) session sourceOperationMaskForDraggingContext:(NSDraggingContext)context;
 //
 - (void) setMouseCursor: (ECursor) cursorType;
 @end

diff --git a/IGraphics/Platforms/IGraphicsMac_view.mm b/IGraphics/Platforms/IGraphicsMac_view.mm
@@ -1285,6 +1285,11 @@ - (BOOL) performDragOperation: (id<NSDraggingInfo>) sender
   return YES;
 }
 
+- (NSDragOperation)draggingSession:(NSDraggingSession*) session sourceOperationMaskForDraggingContext:(NSDraggingContext)context
+{
+  return NSDragOperationCopy;
+}
+
 #ifdef IGRAPHICS_METAL
 - (void) frameDidChange:(NSNotification*) pNotification
 {

diff --git a/IGraphics/Platforms/IGraphicsWin.cpp b/IGraphics/Platforms/IGraphicsWin.cpp
@@ -16,6 +16,7 @@
 
 #include "IPlugParameter.h"
 #include "IGraphicsWin.h"
+#include "IGraphicsWin_dnd.h"
 #include "IPopupMenuControl.h"
 #include "IPlugPaths.h"
 
@@ -1953,6 +1954,30 @@ bool IGraphicsWin::SetFilePathInClipboard(const char* path)
   return result;
 }
 
+bool IGraphicsWin::InitiateExternalFileDragDrop(const char* path, const IRECT& /*iconBounds*/)
+{
+  using namespace DragAndDropHelpers;
+  OleInitialize(nullptr);
+
+  FORMATETC format = { CF_HDROP, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
+
+  DataObject* dataObj = new DataObject(&format, path);
+  DropSource* dropSource = new DropSource();
+
+  DWORD dropEffect;
+  HRESULT ret = DoDragDrop(dataObj, dropSource, DROPEFFECT_COPY, &dropEffect);
+  bool success = SUCCEEDED(ret);
+
+  dataObj->Release();
+  dropSource->Release();
+
+  OleUninitialize();
+
+  ReleaseMouseCapture();
+
+  return success;
+}
+
 static HFONT GetHFont(const char* fontName, int weight, bool italic, bool underline, DWORD quality = DEFAULT_QUALITY, bool enumerate = false)
 {
   HDC hdc = GetDC(NULL);

diff --git a/IGraphics/Platforms/IGraphicsWin.h b/IGraphics/Platforms/IGraphicsWin.h
@@ -77,6 +77,8 @@ class IGraphicsWin final : public IGRAPHICS_DRAW_CLASS
   bool SetTextInClipboard(const char* str) override;
   bool SetFilePathInClipboard(const char* path) override;
 
+  bool InitiateExternalFileDragDrop(const char* path, const IRECT& iconBounds) override;
+
   bool PlatformSupportsMultiTouch() const override;
 
   static LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);