Develop Reference

Android SurfaceView never becomes valid

SurfaceView is never available for drawing after creation.
Other SO questions indicate that it can be managed with the callback functions handed to it, and it must be assigned to setContentView before the lifecycle starts.
Logcat indicates that the callbacks are assigned successfully, however they are never fired.
Full code here but I think relevant parts can be found in the main activity:
package com.example.gavin.pixelarraytest;
import android.app.Activity;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
GameView theGame = new GameView(this, 0,0);
SurfaceHolder testt;
testt = theGame.getHolder();
setContentView(theGame);
while(true){
if(testt.getSurface().isValid()){ // this never becomes true. isCreating is also consistently false at this point
theGame.prepareCanvas();
break;
}
}
}
}
And in the SurfaceView object:
package com.example.gavin.pixelarraytest;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.util.Log;
import android.view.Display;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
public class GameView extends SurfaceView implements Runnable {
private Paint paint;
private Canvas canvas;
private Bitmap _buffer;
private SurfaceHolder ourHolder;
private boolean running;
private boolean paused = false;
private long fps;
public GameView(Context context, int screenX, int screenY){
ourHolder = getHolder();
ourHolder.addCallback(new MyCallback());
paint = new Paint();
}
public void prepareCanvas(){
running = true;
run();
}
#Override
public void run(){
while(running){
long startFrameTime = System.currentTimeMillis();
draw();
long endFrameTime = System.currentTimeMillis() - startFrameTime;
if(endFrameTime >= 1){
fps = 1000 / endFrameTime;
}
}
private void update(){
class MyCallback implements SurfaceHolder.Callback {
#Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
}
private void draw(){
this.setWillNotDraw(false);
if(ourHolder.getSurface().isValid()){
canvas = ourHolder.lockCanvas();
canvas.drawColor(Color.argb(255,100,40,40));
int width = 100;
int height = 100;
int colors[] = new int[width*height];
for (int i = 0; i < colors.length; i++){
int a = 255, r = 40, g = 100, b = 40;
colors[i] = (a << 24) | (r << 16) | (g << 8) | b;
_buffer = Bitmap.createBitmap(colors, width, height, Bitmap.Config.RGB_565);
canvas.drawBitmap(_buffer, 0,0,null);
}
}
}
Am I misunderstanding how SurfaceView is used or am I using it incorrectly in the above?

To inflate a canvas object you can try this:
First create a layout file in res>layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<GameView
android:id="+#id/mGameView"
android:layout_height="match_parent"
android:layout_width="match_parent"
/>
</LinearLayout>
Then you can inflate this by calling
setContentView(R.layout.your_file_name);
And finally access the gameview by using:
GameView gameView = findViewById(R.id.mGameView);
gameView.prepareCanvas();

Can't draw bitmap as overlay

I'm trying to draw bitmap on my activity, showing button as overlay works like a charm, but I can't deal with bitmap. What should I change in my code?
I tried to manually call onDraw by mView.invalidate() in onCreate(), but it wouldn't work.
Thanks in advance!
package com.example.btserver
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.os.IBinder;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.Toast;
public class HUD extends Service implements OnTouchListener {
Button mButton;
OverlayView mView;
#Override
public IBinder
onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
mView = new OverlayView(this);
mButton = new Button(this);
mButton.setText("Overlay button");
mButton.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
setText();
return true;
}
});
WindowManager.LayoutParams params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,//TYPE_SYSTEM_ALERT,//TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE |
WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN, //will cover status bar as well!!!
PixelFormat.TRANSLUCENT);
params.gravity = Gravity.LEFT | Gravity.TOP;
params.y = 100;
params.x = 100;
params.setTitle("Load Average");
WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
wm.addView(mButton, params);
wm.addView(mView, params);
}
#Override
public void onDestroy() {
super.onDestroy();
if(mButton != null)
{
((WindowManager) getSystemService(WINDOW_SERVICE)).removeView(mButton);
mButton = null;
}
}
#Override
public boolean onTouch(View v, MotionEvent event) {
Toast.makeText(this,"Overlay button event", Toast.LENGTH_SHORT).show();
return false;
}
public void setText() {
Toast.makeText(this,"Overlay button event", Toast.LENGTH_SHORT).show();
}
}
class OverlayView extends ViewGroup {
private Paint mLoadPaint;
Bitmap cursor;
public int x = 0,y = 0;
public void Update(int nx, int ny) {
x = nx; y = ny;
}
public OverlayView(Context context) {
super(context);
cursor = BitmapFactory.decodeResource(context.getResources(), R.drawable.cursor);
mLoadPaint = new Paint();
mLoadPaint.setAntiAlias(true);
mLoadPaint.setTextSize(10);
mLoadPaint.setARGB(255, 255, 0, 0);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(cursor, 0,0, mLoadPaint);
}
#Override
protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) {
}
#Override
public boolean onTouchEvent(MotionEvent event) {
return true;
}
}

how to import custom animation xml in wallpaper app?

i have a source which is a sample wallpaper app, i want to import a animation xml
public WallpaperEngine(Resources r) {
image01=BitmapFactory.decodeResource(r,R.drawable.fire01);
image02=BitmapFactory.decodeResource(r,R.drawable.fire02);
bg=BitmapFactory.decodeResource(r,R.drawable.hktv);
px=1;
translateAnimation = AnimationUtils.loadAnimation(this, android.R.anim.translate_animation);
}
but there is a error at line translate_animation
cannot find symbol variable translate_animation
How can i solve this?
------update------
package com.example.android.livewallpaper;
import android.app.Activity;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.service.wallpaper.WallpaperService;
import android.view.SurfaceHolder;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
public class FireLiveWallpaper extends WallpaperService {
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public Engine onCreateEngine() {
return new WallpaperEngine(getResources());
}
public class WallpaperEngine extends Engine {
private final Handler handler=new Handler();
private Bitmap image; //Image
private Bitmap image01; //Image01 for fire01.PNG
private Bitmap image02; //Image02 for fire02.PNG
private Bitmap bg;
private Paint paint = new Paint();
private int px=0; //Flag for switch
private boolean visible;
private int width;
private int height;
private int _xOffset = 0;
private int _yOffset = 0;
final Animation translateAnimation;
private final Runnable drawThread=new Runnable() {
public void run() {
drawFrame();
}
};
public WallpaperEngine(Resources r) {
image01=BitmapFactory.decodeResource(r,R.drawable.fire01);
image02=BitmapFactory.decodeResource(r,R.drawable.fire02);
bg=BitmapFactory.decodeResource(r,R.drawable.hktv);
px=1;
translateAnimation = AnimationUtils.loadAnimation(this,R.anim.translate_animation);
}
#Override
public void onCreate(SurfaceHolder surfaceHolder) {
super.onCreate(surfaceHolder);
}
#Override
public void onDestroy() {
super.onDestroy();
handler.removeCallbacks(drawThread);
}
#Override
public void onSurfaceChanged(SurfaceHolder holder,
int format,int width,int height) {
super.onSurfaceChanged(holder,format,width,height);
this.width =width;
this.height=height;
drawFrame();
}
#Override
public void onSurfaceCreated(SurfaceHolder holder) {
super.onSurfaceCreated(holder);
}
#Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
super.onSurfaceDestroyed(holder);
visible=false;
handler.removeCallbacks(drawThread);
}
#Override
public void onVisibilityChanged(boolean visible) {
this.visible=visible;
if (visible) {
drawFrame();
} else {
handler.removeCallbacks(drawThread);
}
}
#Override
public void onOffsetsChanged(float xOffset,float yOffset,
float xStep,float yStep,int xPixels,int yPixels) {
_xOffset = xPixels;
_yOffset = yPixels;
drawFrame();
}
private void drawFrame() {
SurfaceHolder holder=getSurfaceHolder();
Canvas c=holder.lockCanvas();
c.drawBitmap(bg, _xOffset, _yOffset, paint);
//c.drawColor(Color.BLUE);
if (px == 1) {
image=image01;
px=2;
} else {
image=image02;
px=1 ;
}
c.drawBitmap(image, (width-image.getWidth())/2, (height-image.getHeight())/2, null);
holder.unlockCanvasAndPost(c);
handler.removeCallbacks(drawThread);
if (visible) handler.postDelayed(drawThread,100);
}
}
}

Use R.anim.translate_animation instead of android.R.anim.translate_animation to import animation for res/anim resource :
translateAnimation = AnimationUtils.loadAnimation(this,
R.anim.translate_animation);

How to make SurfaceView with transparent background?

I have simple layout
<?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>
And a have ZenClockSurface class
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);
}
}
}
}
}
}
And code of activity
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);
}
}
I want what background color of android picture was tranparent but i get black background.
I have background on RelativeLayout with some picture bu SurfaceView rotate Android icon with no transparent.
How i can do transparent?

Yeah, i did it i solve problem
Activity code
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);
}
}
Surface Code
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);
}
}
}
}
}
}
It's work.

In API 3 and 4, you cannot put anything behind a SurfaceView. Quoting Dianne Hackborn:
The surface view is actually BEHIND your window, and a hole punched in the window for you to see it. You thus can put things on top of it in your window, but nothing in your window can appear behind it.
http://groups.google.com/group/android-developers/browse_thread/thread/8d88ef9bb22da574
From API 5 onwards you can use setZOrderOnTop. The trick is that you have to do it in your constructor so it gets called before the view is attached to the window:
public ZenClockSurface(Context context, AttributeSet attrs) {
super(context, attrs);
setZOrderOnTop(true);
SurfaceHolder holder = getHolder();
holder.setFormat(PixelFormat.TRANSLUCENT);
}

Android: attempting to draw a canvas on a relative layout and eclipse wants to initialise a variable that shouldn't need it

Hello EclipeE wants to initialise:
CustomDrawableView mCustomDrawableView;
Any ideas?
Cheers
Phil
Here's my code:
package com.android.phil.graphtoggle;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.OvalShape;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageButton;
import android.widget.RelativeLayout;
public class MainActivity extends Activity
{
public int graph_toggle = 0;
public int data_toggle=0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ImageButton graph_toggle_button = (ImageButton) findViewById(R.id.graph_toggle);
final ImageButton graph_settings_button = (ImageButton) findViewById(R.id.graph_type);
final ImageButton data_toggle_button = (ImageButton) findViewById(R.id.data_toggle);
CustomDrawableView mCustomDrawableView;
RelativeLayout mainLayout = (RelativeLayout)findViewById(R.id.relativeLayout1);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT,200);
lp.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
// add here other layout params rules to make your
// custom view stay below the buttons
mCustomDrawableView.setLayoutParams(lp);
mainLayout.addView(mCustomDrawableView);
graph_toggle_button.setOnClickListener(new View.OnClickListener()
{
public void onClick(View arg0)
{
if (graph_toggle==2)
{
graph_toggle=0;
}
else
{
graph_toggle++;
}
if (graph_toggle==0)
{
graph_settings_button.setImageResource(R.drawable.close);
}
if (graph_toggle==1)
{
graph_settings_button.setImageResource(R.drawable.ohlc_bars);
}
if(graph_toggle==2)
{
graph_settings_button.setImageResource(R.drawable.candles);
}
}
});
data_toggle_button.setOnClickListener(new View.OnClickListener()
{
public void onClick(View arg0)
{
if (data_toggle==2)
{
data_toggle=0;
}
else
{
data_toggle++;
}
if (data_toggle==0)
{
data_toggle_button.setImageResource(R.drawable.ohlc_bars_daily);
}
if (data_toggle==1)
{
data_toggle_button.setImageResource(R.drawable.ohlc_bars_weekly);
}
if(data_toggle==2)
{
data_toggle_button.setImageResource(R.drawable.ohlc_bars_monthly);
}
}
});
}
public class CustomDrawableView extends View
{
private ShapeDrawable mDrawable;
public CustomDrawableView(Context context)
{
super(context);
int x = 10;
int y = 100;
int width = 300;
int height = 50;
mDrawable = new ShapeDrawable(new OvalShape());
mDrawable.getPaint().setColor(0xff74AC23);
mDrawable.setBounds(x, y, x + width, y + height);
}
protected void onDraw(Canvas canvas)
{
mDrawable.draw(canvas);
}
}
}

You aren't initializing mCustomDrawableView anywhere so mCustomDrawableView.setLayoutParams(lp); is going to cause a NullPointerException.
You are missing something like
mCustomDrawableView = (CustomDrawableView) this.findViewById(R.id.my_custom_view);