feat: audio file drag-and-drop + expanded format support

.gitignore

@@ -13,3 +13,4 @@ DerivedData/
 *.wav
 *.aiff
 *.mp3
+_codeql_detected_source_root

apps/standalone/Main.cpp

@@ -28,6 +28,7 @@ class StandaloneMainComponent : public juce::AudioAppComponent
 
         addAndMakeVisible(mainView);
         mainView.setOnLoadFile([this] { loadFile(); });
+        mainView.setOnFileDrop([this](const juce::File& file) { loadFromFile(file); });
         mainView.setLoadEnabled(true);
         mainView.setMonoState(false);
 
@@ -70,33 +71,38 @@ class StandaloneMainComponent : public juce::AudioAppComponent
     }
 
 private:
+    void loadFromFile(const juce::File& file)
+    {
+        if (! file.existsAsFile())
+            return;
+
+        std::unique_ptr<juce::AudioFormatReader> reader(formatManager.createReaderFor(file));
+        if (reader == nullptr)
+        {
+            mainView.setFileName("Unsupported file");
+            mainView.clearWaveform();
+            return;
+        }
+
+        const auto sourceSampleRate = reader->sampleRate;
+        auto newSource = std::make_unique<juce::AudioFormatReaderSource>(reader.release(), true);
+        transportSource.stop();
+        transportSource.setSource(newSource.get(), 0, nullptr, sourceSampleRate);
+        readerSource = std::move(newSource);
+        transportSource.start();
+
+        mainView.setFileName(file.getFileName());
+        mainView.setWaveformFile(file);
+    }
+
     void loadFile()
     {
-        fileChooser = std::make_unique<juce::FileChooser>("Select an audio file", juce::File{}, "*.wav;*.aiff;*.aif");
+        fileChooser = std::make_unique<juce::FileChooser>("Select an audio file", juce::File{},
+            "*.wav;*.aiff;*.aif;*.mp3;*.flac;*.ogg;*.caf;*.mp4;*.m4a");
         const auto flags = juce::FileBrowserComponent::openMode | juce::FileBrowserComponent::canSelectFiles;
         fileChooser->launchAsync(flags, [this](const juce::FileChooser& chooser)
         {
-            const auto file = chooser.getResult();
-            if (! file.existsAsFile())
-                return;
-
-            std::unique_ptr<juce::AudioFormatReader> reader(formatManager.createReaderFor(file));
-            if (reader == nullptr)
-            {
-                mainView.setFileName("Unsupported file");
-                mainView.clearWaveform();
-                return;
-            }
-
-            const auto sourceSampleRate = reader->sampleRate;
-            auto newSource = std::make_unique<juce::AudioFormatReaderSource>(reader.release(), true);
-            transportSource.stop();
-            transportSource.setSource(newSource.get(), 0, nullptr, sourceSampleRate);
-            readerSource = std::move(newSource);
-            transportSource.start();
-
-            mainView.setFileName(file.getFileName());
-            mainView.setWaveformFile(file);
+            loadFromFile(chooser.getResult());
         });
     }
 

docs/ARCHITECTURE.md

@@ -16,6 +16,14 @@
 - UI polls snapshots on a timer and renders meters + spectrum bars.
 - Education cards are loaded from JSON and rotated on user interaction.
 
+## File Import / Sharing
+
+- Accepted formats: WAV, AIFF, MP3, FLAC, OGG, CAF, MP4/M4A (whatever `registerBasicFormats()` plus platform decoders support).
+- **Standalone**: "Load Audio" button opens a file picker; files can also be dragged from Finder directly onto the waveform area.
+- **Plugin**: "Load Audio" button and drag-and-drop are both enabled for a *reference waveform* — the file is displayed visually only. Live audio analysis continues from the DAW input bus via `processBlock`.
+- `WaveformView` implements `juce::FileDragAndDropTarget` and exposes an `onFileDropped` callback; `KindPathMainComponent` exposes `setOnFileDrop` to wire callers in.
+
+
 ## Shared Boundaries
 - `AnalysisEngine` is shared across app and plugin.
 - UI is shared and wired to analysis + education data in each target.

plugins/kindpath-q/PluginEditor.cpp

@@ -19,9 +19,13 @@ KindPathQAudioProcessorEditor::KindPathQAudioProcessorEditor(KindPathQAudioProce
       audioProcessor(p),
       mainView(audioProcessor.getAnalysisEngine())
 {
+    formatManager.registerBasicFormats();
+
     addAndMakeVisible(mainView);
-    mainView.setLoadEnabled(false);
-    mainView.setFileName("Live input");
+    mainView.setLoadEnabled(true);
+    mainView.setOnLoadFile([this] { loadFile(); });
+    mainView.setOnFileDrop([this](const juce::File& file) { loadFromFile(file); });
+    mainView.setFileName("Live input — drop a reference file to compare");
     mainView.setMonoState(false);
 
     loadEducationDeck();
@@ -41,6 +45,28 @@ void KindPathQAudioProcessorEditor::resized()
     mainView.setBounds(getLocalBounds());
 }
 
+void KindPathQAudioProcessorEditor::loadFromFile(const juce::File& file)
+{
+    if (! file.existsAsFile())
+        return;
+
+    // In the plugin, we display the waveform as a visual reference only.
+    // Live audio analysis continues via processBlock from the DAW input bus.
+    mainView.setFileName(file.getFileName());
+    mainView.setWaveformFile(file);
+}
+
+void KindPathQAudioProcessorEditor::loadFile()
+{
+    fileChooser = std::make_unique<juce::FileChooser>("Select an audio file", juce::File{},
+        "*.wav;*.aiff;*.aif;*.mp3;*.flac;*.ogg;*.caf;*.mp4;*.m4a");
+    const auto flags = juce::FileBrowserComponent::openMode | juce::FileBrowserComponent::canSelectFiles;
+    fileChooser->launchAsync(flags, [this](const juce::FileChooser& chooser)
+    {
+        loadFromFile(chooser.getResult());
+    });
+}
+
 void KindPathQAudioProcessorEditor::loadEducationDeck()
 {
     juce::String errorMessage;

plugins/kindpath-q/PluginEditor.h

@@ -15,11 +15,16 @@ class KindPathQAudioProcessorEditor : public juce::AudioProcessorEditor
     void resized() override;
 
 private:
+    void loadFile();
+    void loadFromFile(const juce::File& file);
     void loadEducationDeck();
 
     KindPathQAudioProcessor& audioProcessor;
     kindpath::education::EducationDeck deck;
     kindpath::ui::KindPathMainComponent mainView;
 
+    juce::AudioFormatManager formatManager;
+    std::unique_ptr<juce::FileChooser> fileChooser;
+
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(KindPathQAudioProcessorEditor)
 };

ui/KindPathMainComponent.cpp

@@ -57,6 +57,11 @@ namespace kindpath::ui
         waveformView.clear();
     }
 
+    void KindPathMainComponent::setOnFileDrop(std::function<void(const juce::File&)> handler)
+    {
+        waveformView.onFileDropped = std::move(handler);
+    }
+
     void KindPathMainComponent::paint(juce::Graphics& g)
     {
         g.fillAll(juce::Colour(0xff0b0d12));

ui/KindPathMainComponent.h

@@ -23,6 +23,7 @@ namespace kindpath::ui
         void setMonoState(bool enabled);
         void setWaveformFile(const juce::File& file);
         void clearWaveform();
+        void setOnFileDrop(std::function<void(const juce::File&)> handler);
 
         void resized() override;
         void paint(juce::Graphics& g) override;

ui/WaveformView.cpp

@@ -1,5 +1,17 @@
 #include "WaveformView.h"
 
+namespace
+{
+    const juce::StringArray& audioExtensions()
+    {
+        static const juce::StringArray exts {
+            ".wav", ".aiff", ".aif", ".mp3",
+            ".flac", ".ogg", ".caf", ".mp4", ".m4a"
+        };
+        return exts;
+    }
+}
+
 namespace kindpath::ui
 {
     WaveformView::WaveformView(juce::AudioFormatManager& formatManager)
@@ -28,6 +40,44 @@ namespace kindpath::ui
         repaint();
     }
 
+    bool WaveformView::isInterestedInFileDrag(const juce::StringArray& files)
+    {
+        for (const auto& f : files)
+        {
+            if (audioExtensions().contains(juce::File(f).getFileExtension().toLowerCase()))
+                return true;
+        }
+        return false;
+    }
+
+    void WaveformView::fileDragEnter(const juce::StringArray&, int, int)
+    {
+        isDragOver = true;
+        repaint();
+    }
+
+    void WaveformView::fileDragExit(const juce::StringArray&)
+    {
+        isDragOver = false;
+        repaint();
+    }
+
+    void WaveformView::filesDropped(const juce::StringArray& files, int, int)
+    {
+        isDragOver = false;
+        for (const auto& f : files)
+        {
+            const juce::File file(f);
+            if (audioExtensions().contains(file.getFileExtension().toLowerCase()))
+            {
+                if (onFileDropped)
+                    onFileDropped(file);
+                break;
+            }
+        }
+        repaint();
+    }
+
     void WaveformView::paint(juce::Graphics& g)
     {
         g.fillAll(juce::Colour(0xff0f1115));
@@ -45,6 +95,16 @@ namespace kindpath::ui
             g.setFont(15.0f);
             g.drawFittedText(statusText, getLocalBounds().reduced(12), juce::Justification::centred, 2);
         }
+
+        if (isDragOver)
+        {
+            g.setColour(juce::Colour(0x447ed0ff));
+            g.fillRect(getLocalBounds());
+            g.setColour(juce::Colour(0xff7ed0ff));
+            g.drawRect(getLocalBounds(), 2);
+            g.setFont(15.0f);
+            g.drawFittedText("Drop audio file here", getLocalBounds().reduced(12), juce::Justification::centred, 2);
+        }
     }
 
     void WaveformView::resized()

ui/WaveformView.h

@@ -4,20 +4,31 @@
 
 namespace kindpath::ui
 {
-    class WaveformView : public juce::Component
+    class WaveformView : public juce::Component,
+                         public juce::FileDragAndDropTarget
     {
     public:
         explicit WaveformView(juce::AudioFormatManager& formatManager);
 
         void loadFile(const juce::File& file);
         void clear();
 
+        /** Called on the message thread when an audio file is dropped onto this view. */
+        std::function<void(const juce::File&)> onFileDropped;
+
         void paint(juce::Graphics& g) override;
         void resized() override;
 
+        // FileDragAndDropTarget
+        bool isInterestedInFileDrag(const juce::StringArray& files) override;
+        void fileDragEnter(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;
+
     private:
         juce::AudioThumbnailCache thumbnailCache { 8 };
         juce::AudioThumbnail thumbnail;
         juce::String statusText = "Load audio to see the waveform";
+        bool isDragOver = false;
     };
 }