I am trying to write a real time pitch visualization using TextureView. The
flow of the code I have implemented seems to be okay but I am unable to see
the pitch contour I am trying to plot.
So, I have created a custom view as ...
public class PitchSurfaceView extends TextureView implements
TextureView.SurfaceTextureListener { ...}
In the constructor of the view I have set the listener ...
public PitchSurfaceView(Context context, AttributeSet attrs) {
...............
setOpaque(false);
setSurfaceTextureListener(this);
}
Inside my onSurfaceTextureAvailable(), I am doing the following
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int
width, int height) {
Log.i(TAG, "Width of the texture view: " + width);
Log.i(TAG, "Height of the texture view: " + height);
// creating the bitmaps to draw them ....
if (!isBitmapsCreated) {
Log.i(TAG, "Drawing bitmaps for the first time.");
createBitmaps();
drawMyBitmaps();
isBitmapsCreated = true;
}
* drawOnView();*
}
The important method here is drawOnView which actually uses the canvas to
draw on the View bitmap. As for other methods above, I have already tested
them using a custom View by just extending the View class. They work fine
there. Here is my implementation of drawOnView()
protected void drawOnView() {
if(null == mPitchContourGT) {
Log.e(TAG, "mPitchContourGT is null", new
NullPointerException());
return;
}
final Canvas canvas = lockCanvas();
try {
// clearing the canvas ...
Log.d("drawOnView", "Before!!");
canvas.drawColor(0x00000000, PorterDuff.Mode.CLEAR);
// Drawing the front padding ...
canvas.drawBitmap(mBitmaps[0], 0, 0, mPainter);
int pos = mBitmaps[0].getWidth();
for (int i = 0; i < (mBitmaps.length - 1) * mNumberLoops; i++) {
// mBitmaps.length - 1 because we have an extra bitmap at
the beginning ..
final int index = i % (mBitmaps.length - 1) + 1;
canvas.drawBitmap(mBitmaps[index], pos, 0, mPainter);
pos += mBitmaps[index].getWidth();
}
} finally {
unlockCanvasAndPost(canvas);
}
Log.d("drawOnView", "After!!");
}
Here I am first getting lock at the canvas and drawing my earlier created
bitmaps on the canvas. I see the debug logs that I have put but I cannot
see the brawn bitmaps on my view. Anything wrong that I am doing?
On Tuesday, October 16, 2012 at 5:31:33 PM UTC+2, Conrad Chapman wrote:
>
> I looked at this more and Romain Guy unsurprisingly got it 100% right.
> My code pasted here is wrong.
> DO NOT add
> setWillNotDraw(true); in the TextureView and
> mSurface.updateTexImage(); in the drawing thread.
> They will mess it up!
>
>
> On Thursday, 4 October 2012 17:17:33 UTC+2, Conrad Chapman wrote:
>>
>> Thank you so much Romain for your reply and example. I might be the only
>> real canvas textureview example on the net. It worked but not quite as you
>> said. It might be something to do with my class structure as this part of
>> the program does not have internal classes..
>> I will explain and show a little. Maybe my approach is bad or wrong I
>> don't know.
>> CLASSES
>> Main Activity
>> spawns
>> - CustomTextureView class extending TextureView
>> -this spawns the worker thread (it does not extend thread
>> but just a worker class)
>>
>> the TextureView constructor
>>
>> public CustomTextureView (Context context, AttributeSet attrs) {
>> super(context, attrs);
>> mContext = context;
>> setWillNotDraw(true);
>> setFocusableInTouchMode(true);
>> setFocusable(true);
>> setSurfaceTextureListener(this);
>>
>> }
>> and the listener callback within this class
>> @Override
>> public void onSurfaceTextureAvailable(SurfaceTexture surface, int width,
>> int height) {
>> // TODO Auto-generated method stub
>> isRunning = true;
>> mSurface = surface;
>> mChart.setTextureSurface(surface);//mChart is the worker class/thread
>> mChart.setSurfaceSize(width, height);
>> mChart.Redraw(true);//this does all the canvas drawing on a bitmap for
>> buffering.
>> invalidate();//this is essential to make it display on 1st run..why?
>> }
>>
>> The worker class spawned from the CustomTextureView and the critical void
>> protected void RenderCanvas(){
>> final Canvas canvas = CustomTextureView .lockCanvas(null);
>> try {
>> canvas.drawBitmap(buffBitmap, 0, 0, null);
>> } finally {
>> CustomTextureView .unlockCanvasAndPost(canvas);
>> mSurface.updateTexImage();
>> }
>> }
>>
>> So I do not work from the main activity and don't understand why I need
>> to call invalidate() in onSurfaceTextureAvailable for the 1st run to
>> display properly.
>>
>> Romain Guy you said NOT to call updateTexImage but if I don't my 2d chart
>> does not update with the new buffBitmap when it is available.
>> this I definitely don't understand????
>>
>> Anyway it works and thanks for putting me on the right track but am i
>> still doing some android bad?
>>
>> C
>>
>> On Thursday, 4 October 2012 00:06:00 UTC+2, Romain Guy (Google) wrote:
>>>
>>> Here is a fully working example of Canvas & TextureView:
>>>
>>> http://pastebin.com/J4uDgrZ8
>>>
>>> On Wed, Oct 3, 2012 at 3:01 PM, Romain Guy <roma...@android.com> wrote:
>>> > The problem is that you are calling updateTexImage() yourself. Do
>>> > *not* do this. You are interfering with TextureView, preventing it
>>> > from receiving the events that it uses to refresh the screen.
>>> >
>>> > On Tue, Oct 2, 2012 at 7:40 AM, Conrad Chapman <chapman...@gmail.com>
>>> wrote:
>>> >> Also asked in StackOverflow here
>>> >>
>>> http://stackoverflow.com/questions/12688409/android-textureview-canvas-drawing-problems
>>>
>>> >>
>>> >> I have an app that used SurfaceView to draw dynamic 2D graphs. It
>>> worked ok
>>> >> but transormations etc as we know are not supported. So I went to
>>> >> TextureView. My old code used another class/thread to do the drawing
>>> via the
>>> >> Surfaceholder.lockCanvas(); So I changed this to
>>> TextureView.lockcanvas.
>>> >> When this runs the canvas is not accelerated (the view is). It does
>>> not
>>> >> display initially but if I touch the screen it displays??? The touch
>>> is
>>> >> handled by the main activity.
>>> >>
>>> >> Obviously it works as it will display eventually but why doesn't it
>>> display
>>> >> immediately?
>>> >>
>>> >> The TextureView class implements SurfaceTextureListener as such
>>> below.
>>> >> @Override
>>> >> public void onSurfaceTextureAvailable(SurfaceTexture surface, int
>>> width,
>>> >> int height) {
>>> >> // TODO Auto-generated method stub
>>> >> isRunning = true;
>>> >> mySurface = surface;
>>> >> mChart.setTextureSurface(surface);
>>> >> mChart.setSurfaceSize(width, height);
>>> >> mPaint.setColor(ZOOM_BUTTONS_COLOR);
>>> >> //mySurface.setOnFrameAvailableListener(frameready);
>>> >> mChart.Redraw(true);
>>> >> }
>>> >> @Override
>>> >> public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
>>> >> // TODO Auto-generated method stub
>>> >> isRunning = false;
>>> >> return false;
>>> >> }
>>> >> this block below also workswhen manipluating the view later on (pan
>>> and
>>> >> zoom)
>>> >> public void Render(Bitmap buffmap){
>>> >> //mCanvas = null;
>>> >> post(new Runnable() {
>>> >> public void run() {
>>> >> invalidate();
>>> >> mySurface.updateTexImage();
>>> >> }
>>> >> });
>>> >>
>>> >>
>>> >> The drawing from the worker thread/class is
>>> >> protected void RenderCanvas(){
>>> >> //mCanvas = null;
>>> >> Canvas c = null;
>>> >> //synchronized (mCanvas) {
>>> >> //mCanvas = null;
>>> >> try {
>>> >> c = mChartView.lockCanvas(null);
>>> >>
>>> >> synchronized (mCanvas) {
>>> >> c.drawBitmap(buffBitmap, 0, 0, null);
>>> >>
>>> >> }
>>> >> } finally {
>>> >> if (c != null) {
>>> >> mChartView.unlockCanvasAndPost(c);
>>> >> }
>>> >> }
>>> >> mChartView.Render(null);
>>> >> }
>>> >>
>>> >> Can I work like this? Non-GL content in a TextureView?
>>> >> Please help desperate for an answer.
>>> >>
>>> >> --
>>> >> You received this message because you are subscribed to the Google
>>> >> Groups "Android Developers" group.
>>> >> To post to this group, send email to android-d...@googlegroups.com
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>>> >> For more options, visit this group at
>>> >> http://groups.google.com/group/android-developers?hl=en
>>> >
>>> >
>>> >
>>> > --
>>> > Romain Guy
>>> > Android framework engineer
>>> > roma...@android.com
>>>
>>>
>>>
>>> --
>>> Romain Guy
>>> Android framework engineer
>>> roma...@android.com
>>>
>>
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