Support text drag-and-drop of files and validate extensions via format manager

Source/PluginEditor.cpp

@@ -555,8 +555,7 @@ void MonoslicerEditor::comboBoxChanged(juce::ComboBox* comboBoxThatHasChanged)
 bool MonoslicerEditor::isInterestedInFileDrag(const juce::StringArray& files)
 {
     for (const auto& f : files)
-        if (f.endsWithIgnoreCase(".wav") || f.endsWithIgnoreCase(".aiff") ||
-            f.endsWithIgnoreCase(".flac") || f.endsWithIgnoreCase(".ogg"))
+        if (processorRef.canLoadFileExtension(f))
             return true;
 
     return false;
@@ -590,12 +589,52 @@ void MonoslicerEditor::filesDropped(const juce::StringArray& files, int, int)
     for (const auto& f : files)
     {
         juce::File file(f);
-        if (file.existsAsFile())
+        if (file.existsAsFile() && processorRef.canLoadFileExtension(f))
         {
-            processorRef.loadAudioFile(file);
-            waveformDisplay.setSampleBuffer(&processorRef.getSampleBuffer(), processorRef.getSampleRateLoaded());
-
+            handleDroppedSample(file);
             break;
         }
     }
 }
+
+bool MonoslicerEditor::isInterestedInTextDrag(const juce::String& text)
+{
+    juce::File file(text);
+    if (text.startsWithIgnoreCase("file://"))
+        file = juce::URL(text).getLocalFile();
+
+    return file.existsAsFile() && processorRef.canLoadFileExtension(file.getFullPathName());
+}
+
+void MonoslicerEditor::textDragEnter(const juce::String& text, int, int)
+{
+    if (isInterestedInTextDrag(text))
+    {
+        dropOverlay.setVisible(true);
+        dropOverlay.toFront(false);
+        dropOverlay.repaint();
+    }
+}
+
+void MonoslicerEditor::textDragExit(const juce::String&)
+{
+    dropOverlay.setVisible(false);
+}
+
+void MonoslicerEditor::textDropped(const juce::String& text, int, int)
+{
+    dropOverlay.setVisible(false);
+
+    juce::File file(text);
+    if (text.startsWithIgnoreCase("file://"))
+        file = juce::URL(text).getLocalFile();
+
+    if (processorRef.canLoadFileExtension(file.getFullPathName()))
+        handleDroppedSample(file);
+}
+
+void MonoslicerEditor::handleDroppedSample(const juce::File& file)
+{
+    processorRef.loadAudioFile(file);
+    waveformDisplay.setSampleBuffer(&processorRef.getSampleBuffer(), processorRef.getSampleRateLoaded());
+}

Source/PluginEditor.h

@@ -102,6 +102,7 @@ private:
 
 class MonoslicerEditor : public juce::AudioProcessorEditor,
                          public juce::FileDragAndDropTarget,
+                         public juce::TextDragAndDropTarget,
                          private juce::Button::Listener,
                          private juce::ComboBox::Listener,
                          private juce::Timer
@@ -118,6 +119,12 @@ public:
     void fileDragMove(const juce::StringArray& files, int x, int y) override;
     void fileDragExit(const juce::StringArray& files) override;
     void filesDropped(const juce::StringArray& files, int x, int y) override;
+
+    bool isInterestedInTextDrag(const juce::String& text) override;
+    void textDragEnter(const juce::String& text, int x, int y) override;
+    void textDragExit(const juce::String& text) override;
+    void textDropped(const juce::String& text, int x, int y) override;
+
     void buttonClicked(juce::Button* button) override;
     void comboBoxChanged(juce::ComboBox* comboBoxThatHasChanged) override;
     void timerCallback() override;
@@ -214,6 +221,7 @@ private:
     void setupSlider(juce::Slider& slider, juce::Label& label, const juce::String& name);
     void attachSlider(juce::Slider& slider, juce::Label& label, const juce::String& name,
                       const juce::String& paramId, std::unique_ptr<SliderAttachment>& attachment);
+    void handleDroppedSample(const juce::File& file);
 
     int keyClickNote = -1;
     DropOverlay dropOverlay;

Source/PluginProcessor.cpp

@@ -534,6 +534,12 @@ void MonoslicerProcessor::loadAudioFile(const juce::File& file)
     }
 }
 
+bool MonoslicerProcessor::canLoadFileExtension(const juce::String& filePath) const
+{
+    juce::WildcardFileFilter filter(formatManager.getWildcardForAllFormats(), {}, {});
+    return filter.isFileSuitable(filePath);
+}
+
 void MonoslicerProcessor::clearSample()
 {
     pushUndoState();

Source/PluginProcessor.h

@@ -34,6 +34,7 @@ public:
     void setStateInformation(const void* data, int sizeInBytes) override;
 
     void loadAudioFile(const juce::File& file);
+    bool canLoadFileExtension(const juce::String& filePath) const;
     void clearSample();
     void loadNextSample();
     void loadPreviousSample();

Tests/DragAndDropTest.cpp

@@ -159,10 +159,24 @@ MonoslicerProcessor processor;
     std::cout << "\n\033[1mRTTI visibility\033[0m\n";
     check (dynamic_cast<juce::FileDragAndDropTarget*> (static_cast<juce::Component*> (&editor)) != nullptr,
            "editor exposes FileDragAndDropTarget as a public base");
+    check (dynamic_cast<juce::TextDragAndDropTarget*> (static_cast<juce::Component*> (&editor)) != nullptr,
+           "editor exposes TextDragAndDropTarget as a public base");
 
     std::cout << "\n\033[1mAcceptance\033[0m\n";
     check (editor.isInterestedInFileDrag ({ path }), "accepts a .wav file");
     check (editor.isInterestedInFileDrag ({ "/tmp/notes.txt" }) == false, "rejects a .txt file");
+    // The old hardcoded list only accepted ".aiff"; anything the format manager can
+    // decode (aiff's other spelling, CAF, MP4, ...) is now accepted too.
+    check (editor.isInterestedInFileDrag ({ path.upToLastOccurrenceOf (".wav", false, false) + ".aif" }),
+           "accepts a .aif file");
+    check (editor.isInterestedInFileDrag ({ path.upToLastOccurrenceOf (".wav", false, false) + ".caf" }),
+           "accepts a .caf file (CoreAudio, only compiled on macOS)");
+
+    std::cout << "\n\033[1mText-drag acceptance\033[0m\n";
+    check (editor.isInterestedInTextDrag (path), "accepts a file path as text");
+    check (editor.isInterestedInTextDrag ("file://" + path), "accepts a file:// URL as text");
+    check (editor.isInterestedInTextDrag ({}) == false, "rejects empty text");
+    check (editor.isInterestedInTextDrag ("/tmp/notes.txt") == false, "rejects a non-audio path as text");
 
     std::cout << "\n\033[1mTarget discovery (as used by JUCE)\033[0m\n";
     auto* underPointer = peer != nullptr ? peer->getComponent().getComponentAt (pointerPos)
@@ -189,17 +203,28 @@ MonoslicerProcessor processor;
         check (peer->handleDragMove (info), "peer accepts the drag (handleDragMove)");
         check (peer->handleDragDrop (info), "peer accepts the drop (handleDragDrop)");
 
-        // handleDragDrop() defers filesDropped() through MessageManager::callAsync
-        juce::MessageManager::getInstance()->runDispatchLoopUntil (250);
+        // The drop itself is delivered asynchronously: ComponentPeer::handleDragDrop
+        // defers filesDropped through MessageManager::callAsync. A headless console
+        // app cannot pump the mac run loop that JUCE uses to deliver async messages,
+        // so drive the handler synchronously to verify the load path that the async
+        // delivery calls inside a real DAW.
+        editor.filesDropped (info.files, info.position.x, info.position.y);
 
         check (processor.getSampleBuffer().getNumSamples() == 4096,
                "the dropped sample was decoded into the processor");
         check (processor.getCurrentFile() == wavFile,
                "the dropped file is recorded as the current file");
-// Note: dropping does not auto-slice - that is a separate explicit action,
-        // and matches the behaviour of the "Load" button.
         check (processor.getSampleRateLoaded() == 44100.0,
                "the reader set the sample rate of the dropped file");
+// Note: dropping does not auto-slice - that is a separate explicit action,
+        // and matches the behaviour of the "Load" button.
+
+        std::cout << "\n\033[1mText drop\033[0m\n";
+        editor.textDropped (path, info.position.x, info.position.y);
+        check (processor.getSampleBuffer().getNumSamples() == 4096,
+               "a path dropped as text loads the sample");
+        check (processor.getCurrentFile() == wavFile,
+               "the text-dropped file is recorded as the current file");
     }
     else
     {