[Tut] Stateful CustomImageButton with programatic Draw :: anddev.org - Android Development Community

package org.anddev;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Paint.Style;
import android.graphics.Path.Direction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.LinearLayout.LayoutParams;
/*
* Sample CustomImageButton
* Programatic draw a own Button, whit different States
* default, focused and pressed
*
* 14.02.2008 by Mauri for anddev.org
*/
public class CustomImageButton extends Activity {
private TextView mDebug;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);

// prepare the Layout
// two Buttons
// Debug-TextView Below

LinearLayout linLayoutMain = new LinearLayout(this);
linLayoutMain.setOrientation(LinearLayout.VERTICAL);

LinearLayout linLayoutButtons = new LinearLayout(this);
linLayoutButtons.setOrientation(LinearLayout.HORIZONTAL);

// buttons
MyCustomButton btn1 = new MyCustomButton(this, "btn1");
MyCustomButton btn2 = new MyCustomButton(this, "btn2");

// a TextView for debugging output
mDebug = new TextView(this);

// add button to the layout
linLayoutButtons.addView(btn1,
new LinearLayout.LayoutParams(100, 100));
linLayoutButtons.addView(btn2,
new LinearLayout.LayoutParams(100, 100));

// add buttons layout and Text view to the Main Layout
linLayoutMain.addView(linLayoutButtons,
new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
      LayoutParams.WRAP_CONTENT));
linLayoutMain.addView(mDebug,
new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
      LayoutParams.WRAP_CONTENT));

setContentView(linLayoutMain);
}

// Custom Button Class must extends Button,
// because drawableStateChanged() is needed
public class MyCustomButton extends Button {

static final int StateDefault = 0;
static final int StateFocused = 1;
static final int StatePressed = 2;

private int mState = StateDefault;
   private Bitmap mBitmapDefault;
   private Bitmap mBitmapFocused;
   private Bitmap mBitmapPressed;
   private String mCaption;

   public MyCustomButton(Context context, String caption) {
   super(context);
   mCaption = caption;

   setClickable(true);
   // black Background on the View
   setBackgroundColor(0xff000000);

   // create for each State a Bitmap
   // white Image
   mBitmapDefault = Bitmap.createBitmap(100, 100, true);
   // Blue Image
   mBitmapFocused = Bitmap.createBitmap(100, 100, true);
   // Green Image
   mBitmapPressed = Bitmap.createBitmap(100, 100, true);

   // create the Canvas
   Canvas canvas = new Canvas();

   // define on witch Bitmap should the Canvas draw
   // default Bitmap
   canvas.setDevice(mBitmapDefault);

   // create the Drawing Tool (Brush)
   Paint paint = new Paint();
   paint.setAntiAlias(true); // for a nicer paint

   // draw a rectangle with rounded edges
   // white Line
   paint.setColor(0xffffffff);
   // 3px line width
   paint.setStrokeWidth(3);
   // just the line, not filled
   paint.setStyle(Style.STROKE);

   // create the Path
   Path path = new Path();
   // rectangle with 10 px Radius
   path.addRoundRect(new RectF(10, 10, 90, 90),
         10, 10, Direction.CCW);

   // draw path on Canvas with the defined "brush"
   canvas.drawPath(path, paint);

   // prepare the "brush" for the Text
   Paint paintText = new Paint();
   paintText.setAntiAlias(true);
   paintText.setTextSize(20);
   paintText.setColor(0xffffffff); // white

   // draw Text
   canvas.drawText(caption, 30, 55, paintText);

   // do some more drawing stuff here...


   // for the Pressed Image
   canvas.setDevice(mBitmapPressed);

   // Greed Color
   paint.setColor(0xff00ff00);
   paintText.setColor(0xff00ff00); // white Line
   canvas.drawPath(path, paint);
   canvas.drawText(caption, 30, 55, paintText);

   // do some more drawing stuff here...

   // for the Pressed Image
   canvas.setDevice(mBitmapFocused);

   // Blue Color
   paint.setColor(0xff0000ff);
   paintText.setColor(0xff0000ff); // white Line
   canvas.drawPath(path, paint);
   canvas.drawText(caption, 30, 55, paintText);

   // do some more drawing stuff here...


   // define OnClickListener for the Button
   setOnClickListener(onClickListener);

}

   @Override
   protected void onDraw(Canvas canvas) {
      switch (mState) {
      case StateDefault:
         canvas.drawBitmap(mBitmapDefault, 0, 0, null);
         mDebug.append(mCaption + ":default\n");
         break;
      case StateFocused:
         canvas.drawBitmap(mBitmapFocused, 0, 0, null);
         mDebug.append(mCaption + ":focused\n");
         break;
      case StatePressed:
         canvas.drawBitmap(mBitmapPressed, 0, 0, null);
         mDebug.append(mCaption + ":pressed\n");
         break;
      }
   }

   @Override
   protected void drawableStateChanged() {
      if (isPressed()) {
         mState = StatePressed;
      } else if (hasFocus()) {
         mState = StateFocused;
      } else {
         mState = StateDefault;
      }
      // force the redraw of the Image
      // onDraw will be called!
      invalidate();
   }

   private OnClickListener onClickListener =
      new OnClickListener() {
      @Override
      public void onClick(View arg0) {
         mDebug.append(mCaption + ":click\n");
      }
   };
}
}