Finished implementation of MidiPlayer. Yay!

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8064 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/midiplayer/MidiPlayerWindow.cpp

@@ -20,7 +20,6 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
-#include <stdio.h>
 #include <StorageKit.h>
 
 #include "MidiPlayerApp.h"
@@ -42,6 +41,7 @@ MidiPlayerWindow::MidiPlayerWindow()
 	volume = 75;
 	windowX = -1;
 	windowY = -1;
+	threadId = -1;
 	
 	CreateViews();
 	LoadSettings();
@@ -52,15 +52,23 @@ MidiPlayerWindow::MidiPlayerWindow()
 
 MidiPlayerWindow::~MidiPlayerWindow()
 {
-	Stop(false);
+	StopSynth();
 }
 
 //------------------------------------------------------------------------------
 
 bool MidiPlayerWindow::QuitRequested()
 {
-	be_app->PostMessage(B_QUIT_REQUESTED);
+	// There is a race condition when you quit MidiPlayer while we're still
-	return true;
+	// fading out, because fading happens in a separate thread. In this odd
+	// case, we simply won't let the user quit the app :-)
+
+	if (threadId == -1)
+	{
+		be_app->PostMessage(B_QUIT_REQUESTED);
+		return true;
+	}
+	return false;
 }
 
 //------------------------------------------------------------------------------
@@ -338,62 +346,109 @@ void MidiPlayerWindow::SaveSettings()
 
 //------------------------------------------------------------------------------
 
-void MidiPlayerWindow::LoadFile(entry_ref* ref)
+int32 MidiPlayerWindow::_LoadThread(void* data)
 {
-	if (playing)
+	return ((MidiPlayerWindow*) data)->LoadThread();
-	{
-		Stop(false);
-	}
-
-	synth.UnloadFile();
-	
-	if (synth.LoadFile(ref) == B_OK)
-	{
-		// Ideally, we would call SetVolume() in InitControls(), 
-		// but for some reason that doesn't work; BMidiSynthFile
-		// will use the default volume instead. So we do it here.
-		synth.SetVolume(volume / 100.0f);
-
-		playButton->SetEnabled(true);
-		scopeView->SetHaveFile(true);
-	}
-	else
-	{
-		(new BAlert(
-			NULL, "Could not load song", "Okay", NULL, NULL,
-			B_WIDTH_AS_USUAL, B_STOP_ALERT))->Go();
-
-		playButton->SetEnabled(false);
-		scopeView->SetHaveFile(false);
-	}
-	
-	Play();
 }
 
 //------------------------------------------------------------------------------
 
-void MidiPlayerWindow::Play()
+int32 MidiPlayerWindow::LoadThread()
 {
+	// We do this in a separate fire-and-forget thread, just in case a song
+	// was already playing. The call to StopSynth() will block, and we need
+	// to keep the window's looper free for repainting the ScopeView during
+	// the fade out. The R5 MidiPlayer does that too and it looks neat.
+
+	if (playing)
+	{
+		StopSynth();
+	}
+
+	synth.UnloadFile();
+	
+	if (synth.LoadFile(&ref) == B_OK)
+	{
+		// Ideally, we would call SetVolume() in InitControls(), 
+		// but for some reason that doesn't work: BMidiSynthFile
+		// will use the default volume instead. So we do it here.
+		synth.SetVolume(volume / 100.0f);
+
+		Lock();
+		playButton->SetEnabled(true);
+		playButton->SetLabel("Stop");
+		scopeView->SetHaveFile(true);
+		scopeView->Invalidate();
+		Unlock();
+
+		StartSynth();
+	}
+	else
+	{
+		Lock();
+		playButton->SetEnabled(false);
+		playButton->SetLabel("Play");
+		scopeView->SetHaveFile(false);
+		scopeView->Invalidate();
+		Unlock();
+
+		(new BAlert(
+			NULL, "Could not load song", "Okay", NULL, NULL,
+			B_WIDTH_AS_USUAL, B_STOP_ALERT))->Go();
+	}
+
+	threadId = -1;
+	return 0;
+}
+
+//------------------------------------------------------------------------------
+
+int32 MidiPlayerWindow::_StopThread(void* data)
+{
+	return ((MidiPlayerWindow*) data)->StopThread();
+}
+
+//------------------------------------------------------------------------------
+
+int32 MidiPlayerWindow::StopThread()
+{
+	Lock();
+	playButton->SetEnabled(false);
+	Unlock();
+	
+	StopSynth();
+	
+	Lock();
+	playButton->SetEnabled(true);
+	playButton->SetLabel("Play");
+	Unlock();
+
+	threadId = -1;
+	return 0;
+}
+
+//------------------------------------------------------------------------------
+
+void MidiPlayerWindow::StartSynth()
+{
+	// When playback of the song ends, we don't automatically go back into
+	// "stopped" mode. It is possible to do this with synth.SetFileHook(),
+	// but that made the code kinda messy (with all the threads and stuff). 
+	// Note: SetFileHook(NULL) crashes the softsynth. In any case, should 
+	// we ever add this in, remember to call SetFileHook() *after* Start()
+	// or it won't work.
+
 	synth.Start();
-	playButton->SetLabel("Stop");
 	playing = true;
 }
 
 //------------------------------------------------------------------------------
 
-void MidiPlayerWindow::Stop(bool changeButton)
+void MidiPlayerWindow::StopSynth()
 {
-	if (changeButton)
+	if (!synth.IsFinished())
 	{
-		playButton->SetEnabled(false);
+		synth.Fade();
-	}
-		
-	synth.Fade();
-	
-	if (changeButton)
-	{
-		playButton->SetEnabled(true);
-		playButton->SetLabel("Play");
 	}
 
 	playing = false;
@@ -405,11 +460,15 @@ void MidiPlayerWindow::OnPlayStop()
 {
 	if (playing)
 	{
-		Stop(true);
+		threadId = spawn_thread(
+			_StopThread, "StopThread", B_NORMAL_PRIORITY, this);
+
+		resume_thread(threadId);
 	}
 	else
 	{
-		Play();
+		StartSynth();
+		playButton->SetLabel("Stop");
 	}
 }
 
@@ -419,6 +478,7 @@ void MidiPlayerWindow::OnShowScope()
 {
 	scopeEnabled = !scopeEnabled;
 	scopeView->SetEnabled(scopeEnabled);
+	scopeView->Invalidate();
 	SaveSettings();
 }
 
@@ -444,10 +504,12 @@ void MidiPlayerWindow::OnVolume()
 
 void MidiPlayerWindow::OnDrop(BMessage* msg)
 {
-	entry_ref ref;
 	if (msg->FindRef("refs", &ref) == B_OK)
 	{
-		LoadFile(&ref);
+		threadId = spawn_thread(
+			_LoadThread, "LoadThread", B_NORMAL_PRIORITY, this);
+			
+		resume_thread(threadId);
 	}
 }
 

src/apps/midiplayer/MidiPlayerWindow.h

@@ -65,9 +65,14 @@ private:
 	void LoadSettings();
 	void SaveSettings();
 
-	void LoadFile(entry_ref* ref);
+	static int32 _LoadThread(void* data);
-	void Play();
+	int32 LoadThread();
-	void Stop(bool changeButton);
+
+	static int32 _StopThread(void* data);
+	int32 StopThread();
+
+	void StartSynth();
+	void StopSynth();
 
 	void OnPlayStop();
 	void OnShowScope();
@@ -94,6 +99,8 @@ private:
 	float windowX;
 	float windowY;
 	BMidiSynthFile synth;
+	entry_ref ref;
+	thread_id threadId;
 };
 
 #endif // MIDI_PLAYER_WINDOW_H

src/apps/midiplayer/ScopeView.cpp

@@ -20,23 +20,77 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <Synth.h>
+#include <Window.h>
+
 #include "ScopeView.h"
 
 //------------------------------------------------------------------------------
 
 ScopeView::ScopeView()
-	: BView(BRect(0, 0, 127, 47), NULL, B_FOLLOW_LEFT | B_FOLLOW_TOP,
+	: BView(BRect(0, 0, 127, 63), NULL, B_FOLLOW_LEFT | B_FOLLOW_TOP,
-	        B_WILL_DRAW | B_PULSE_NEEDED)
+	        B_WILL_DRAW)
 {
 	SetViewColor(0, 0, 0);
+
 	enabled = true;
 	haveFile = false;
+	
+	sampleCount = (int32) Bounds().Width();
+	leftSamples = new int16[sampleCount];
+	rightSamples = new int16[sampleCount];
 }
 
 //------------------------------------------------------------------------------
 
 ScopeView::~ScopeView()
 {
+	delete[] leftSamples;
+	delete[] rightSamples;
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::AttachedToWindow()
+{
+	finished = false;
+	threadId = spawn_thread(_Thread, "ScopeThread", B_NORMAL_PRIORITY, this);
+	if (threadId >= B_OK)
+	{
+		resume_thread(threadId);
+	}
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DetachedFromWindow()
+{
+	if (threadId >= B_OK)
+	{
+		finished = true;
+		status_t exitValue;
+		wait_for_thread(threadId, &exitValue);
+	}
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::Draw(BRect updateRect)
+{
+	super::Draw(updateRect);
+
+	if (!haveFile)
+	{
+		DrawNoFile();
+	}
+	else if (!enabled)
+	{
+		DrawDisabled();
+	}
+	else 
+	{
+		DrawPlaying();
+	}
 }
 
 //------------------------------------------------------------------------------
@@ -54,3 +108,94 @@ void ScopeView::SetHaveFile(bool flag)
 }
 
 //------------------------------------------------------------------------------
+
+int32 ScopeView::_Thread(void* data)
+{
+	return ((ScopeView*) data)->Thread();
+}
+
+//------------------------------------------------------------------------------
+
+int32 ScopeView::Thread()
+{
+	// Because Pulse() was too slow, I created a thread that tells the 
+	// ScopeView to repaint itself. Note that we need to call LockLooper
+	// with a timeout, otherwise we'll deadlock in DetachedFromWindow().
+
+	while (!finished)
+	{
+		if (enabled && haveFile)
+		{
+			if (LockLooperWithTimeout(50000) == B_OK)
+			{
+				Invalidate();
+				UnlockLooper();
+			}
+		}
+		snooze(50000);
+	}
+	return 0;
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawNoFile()
+{
+	const char* string = "Drop MIDI file here";
+
+	font_height height;
+	GetFontHeight(&height);
+
+	float strWidth = StringWidth(string);
+	float strHeight = height.ascent + height.descent;
+
+	float x = (Bounds().Width() - strWidth)/2;
+	float y = height.ascent + (Bounds().Height() - strHeight)/2;
+
+	SetHighColor(255, 255, 255);
+	SetLowColor(ViewColor());
+	SetDrawingMode(B_OP_OVER);
+
+	DrawString(string, BPoint(x, y));
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawDisabled()
+{
+	SetHighColor(64, 64, 64);
+
+	StrokeLine(
+		BPoint(0, Bounds().Height() / 2), 
+		BPoint(Bounds().Width(), Bounds().Height() / 2));
+}
+
+//------------------------------------------------------------------------------
+
+void ScopeView::DrawPlaying()
+{
+	int32 width = (int32) Bounds().Width();
+	int32 height = (int32) Bounds().Height();
+
+	// Scope drawing magic based on code by Michael Pfeiffer.
+	
+	int32 size = be_synth->GetAudio(leftSamples, rightSamples, sampleCount);
+	if (size > 0)
+	{
+		SetHighColor(255, 0, 130);
+		SetLowColor(0, 130, 0);
+		#define N 16
+		int32 x, y, sx = 0, f = (height << N) / 65535, dy = height / 2;
+		for (int32 i = 0; i < width; i++)
+		{
+			x = sx / width;
+			y = ((leftSamples[x] * f) >> N) + dy;
+			FillRect(BRect(i, y, i, y));
+			y = ((rightSamples[x] * f) >> N) + dy;
+			FillRect(BRect(i, y, i, y), B_SOLID_LOW);
+			sx += size;
+		}
+	}
+}
+
+//------------------------------------------------------------------------------

src/apps/midiplayer/ScopeView.h

@@ -32,6 +32,10 @@ public:
 	ScopeView();
 	virtual ~ScopeView();
 
+	virtual void AttachedToWindow();
+	virtual void DetachedFromWindow();
+	virtual void Draw(BRect updateRect);
+
 	void SetEnabled(bool flag);
 	void SetHaveFile(bool flag);
 
@@ -39,8 +43,20 @@ private:
 
 	typedef BView super;
 
+	static int32 _Thread(void* data);
+	int32 Thread();
+	
+	void DrawNoFile();
+	void DrawDisabled();
+	void DrawPlaying();
+	
+	bool finished;
 	bool enabled;
 	bool haveFile;
+	int32 sampleCount;
+	int16* leftSamples;
+	int16* rightSamples;
+	thread_id threadId;
 };
 
 #endif // SCOPE_VIEW_H