¿Cómo hacer SurfaceView con fondo transparente?

Question

tengo diseño simple

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/RelativeLayout1" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:background="@drawable/backgroundtimer" 
    android:orientation="vertical" > 

    <TextView 
     android:id="@+id/TextView1" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:text="@string/hello" /> 

    <com.fmech.zenclock.surface.ZenClockSurface 
     android:id="@+id/zenClockSurface1" 
     android:layout_width="100dp" 
     android:layout_height="100dp" 
     android:layout_centerHorizontal="true" 
     android:layout_centerVertical="true"/> 

</RelativeLayout> 

y A tienen clase ZenClockSurface

package com.fmech.zenclock.surface; 

import android.content.Context; 
import android.content.res.Resources; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Matrix; 
import android.graphics.Paint; 
import android.graphics.Paint.Style; 
import android.graphics.PixelFormat; 
import android.util.AttributeSet; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 

public class ZenClockSurface extends SurfaceView implements SurfaceHolder.Callback{ 

    private DrawClock drawClock; 

    public ZenClockSurface(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     this.getHolder().setFormat(PixelFormat.TRANSLUCENT); 
     getHolder().addCallback(this); 
    } 

    public ZenClockSurface(Context context) { 
     super(context); 
     this.getHolder().setFormat(PixelFormat.TRANSLUCENT); 
     getHolder().addCallback(this); 
    } 

    public ZenClockSurface(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     this.getHolder().setFormat(PixelFormat.TRANSLUCENT); 
     getHolder().addCallback(this); 
    } 

    @Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
      int height) { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void surfaceCreated(SurfaceHolder holder) { 
     //this.getHolder().setFormat(PixelFormat.TRANSPARENT); 
     drawClock = new DrawClock(getHolder(), getResources()); 
     drawClock.setRunning(true); 
     drawClock.start(); 

    } 

    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 
     boolean retry = true; 
     // завершаем работу потока 
     drawClock.setRunning(false); 
     while (retry) { 
      try { 
       drawClock.join(); 
       retry = false; 
      } catch (InterruptedException e) { 
      } 
     } 

    } 

    class DrawClock extends Thread{ 
     private boolean runFlag = false; 
     private SurfaceHolder surfaceHolder; 
     private Bitmap picture; 
     private Matrix matrix; 
     private long prevTime; 
     private Paint painter; 

     public DrawClock(SurfaceHolder surfaceHolder, Resources resources){ 
      this.surfaceHolder = surfaceHolder; 

      this.surfaceHolder.setFormat(PixelFormat.TRANSLUCENT); 
      picture = BitmapFactory.decodeResource(resources, R.drawable.ic_launcher); 

      matrix = new Matrix(); 
      this.painter=new Paint(); 
      this.painter.setStyle(Paint.Style.FILL); 

     } 

     public void setRunning(boolean run) { 
      runFlag = run; 
     } 

     @Override 
     public void run() { 
      Canvas canvas; 
      while (runFlag) { 

        matrix.preRotate(1.0f, picture.getWidth()/2, picture.getHeight()/2); 
       canvas = null; 
       try { 
        //surfaceHolder.getSurface().setAlpha(0.5f); 
        canvas = surfaceHolder.lockCanvas(null); 
        synchronized (surfaceHolder) { 

         canvas.drawColor(Color.TRANSPARENT); 

         canvas.drawBitmap(picture, matrix, this.painter); 
        } 
       } 
       finally { 
        if (canvas != null) { 
         surfaceHolder.unlockCanvasAndPost(canvas); 
        } 
       } 
      } 
     } 
    } 
} 

Y el código de la actividad

package com.fmech.zenclock.surface; 

import android.app.Activity; 
import android.graphics.PixelFormat; 
import android.os.Bundle; 

public class ZenClockSurfaceActivity extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     getWindow().setFormat(PixelFormat.TRANSLUCENT); 
     setContentView(R.layout.main); 


    } 
} 

Quiero lo que el color de fondo de la imagen androide era tranparent pero consigo negro fondo.

Tengo antecedentes sobre RelativeLayout con alguna imagen bu SurfaceView gira el ícono de Android sin transparencia.

¿Cómo puedo hacer transparente?

Answer 1

Sí, lo hice, resolver el problema

Código de actividad

package com.fmech.zenclock.surface; 

import android.app.Activity; 
import android.graphics.PixelFormat; 
import android.os.Bundle; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 

public class ZenClockSurfaceActivity extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     ZenClockSurface sfvTrack = (ZenClockSurface)findViewById(R.id.zenClockSurface1); 
     sfvTrack.setZOrderOnTop(true); // necessary 
     SurfaceHolder sfhTrack = sfvTrack.getHolder(); 
     sfhTrack.setFormat(PixelFormat.TRANSLUCENT); 

    } 
} 

Código superficie

package com.fmech.zenclock.surface; 

import android.content.Context; 
import android.content.res.Resources; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Matrix; 
import android.graphics.Paint; 
import android.graphics.Paint.Style; 
import android.graphics.PixelFormat; 
import android.graphics.Region; 
import android.util.AttributeSet; 
import android.view.Surface.OutOfResourcesException; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 

public class ZenClockSurface extends SurfaceView implements 
     SurfaceHolder.Callback { 

    private DrawClock drawClock; 

    public ZenClockSurface(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     getHolder().addCallback(this); 
    } 

    public ZenClockSurface(Context context) { 
     super(context); 
     getHolder().addCallback(this); 
    } 

    public ZenClockSurface(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     getHolder().addCallback(this); 
    } 

    @Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, 
      int height) { 

    } 

    @Override 
    public void surfaceCreated(SurfaceHolder holder) { 
     drawClock = new DrawClock(getHolder(), getResources()); 
     drawClock.setRunning(true); 
     drawClock.start(); 

    } 

    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 
     boolean retry = true; 
     drawClock.setRunning(false); 
     while (retry) { 
      try { 
       drawClock.join(); 
       retry = false; 
      } catch (InterruptedException e) { 
      } 
     } 

    } 

    class DrawClock extends Thread { 
     private boolean runFlag = false; 
     private SurfaceHolder surfaceHolder; 
     private Bitmap picture; 
     private Matrix matrix; 
     private Paint painter; 

     public DrawClock(SurfaceHolder surfaceHolder, Resources resources) { 
      this.surfaceHolder = surfaceHolder; 

      picture = BitmapFactory.decodeResource(resources, 
        R.drawable.ic_launcher); 
      matrix = new Matrix(); 
      this.painter = new Paint(); 
      this.painter.setStyle(Paint.Style.FILL); 
      this.painter.setAntiAlias(true); 
      this.painter.setFilterBitmap(true); 
     } 

     public void setRunning(boolean run) { 
      runFlag = run; 
     } 

     @Override 
     public void run() { 
      Canvas canvas; 
      while (runFlag) { 


       matrix.preRotate(1.0f, picture.getWidth()/2, 
         picture.getHeight()/2); 
       canvas = null; 
       try { 
        canvas = surfaceHolder.lockCanvas(null); 
        synchronized (surfaceHolder) { 
         canvas.drawColor(0, android.graphics.PorterDuff.Mode.CLEAR); 
         canvas.drawBitmap(picture, matrix, this.painter); 
        } 
       } catch (IllegalArgumentException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } finally { 
        if (canvas != null) { 
         surfaceHolder.unlockCanvasAndPost(canvas); 
        } 
       } 
      } 
     } 
    } 
} 

Es trabajo.

Answer 2

En API 3 y 4, no se puede poner nada detrás de SurfaceView. Citando Dianne Hackborn:

vista La superficie es en realidad detrás de la ventana, y un agujero perforado en la ventana para que lo veas. De este modo, puede colocar las cosas encima en su ventana, pero nada en su ventana puede aparecer detrás de ella.

http://groups.google.com/group/android-developers/browse_thread/thread/8d88ef9bb22da574

---

De API 5 en adelante se puede utilizar setZOrderOnTop. El truco es que usted tiene que hacerlo en su constructor por lo que es llamado antes de la vista se fija a la ventana:

public ZenClockSurface(Context context, AttributeSet attrs) { 
    super(context, attrs); 

    setZOrderOnTop(true); 

    SurfaceHolder holder = getHolder(); 
    holder.setFormat(PixelFormat.TRANSLUCENT); 
}