ColorMatrix.setConcat() to combine ColorMatrixes

The exercise "Set the rotation on a color axis of Bitmap with ColorMatrix" create rotated ColorMatrix for one color only, not all. We can create ColorMatrix from more than one by calling ColorMatrix.setConcat().

package com.example.androiddrawbitmap;

import java.io.FileNotFoundException;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Paint;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

public class MainActivity extends Activity {

 Button btnLoadImage;
 ImageView imageResult;
 SeekBar rotBarRed, rotBarGreen, rotBarBlue;
 TextView rotText;

 final int RQS_IMAGE1 = 1;

 Uri source;
 Bitmap bitmapMaster;
 Canvas canvasMaster;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  btnLoadImage = (Button) findViewById(R.id.loadimage);
  imageResult = (ImageView) findViewById(R.id.result);

  btnLoadImage.setOnClickListener(new OnClickListener() {

   @Override
   public void onClick(View arg0) {
    Intent intent = new Intent(
      Intent.ACTION_PICK,
      android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(intent, RQS_IMAGE1);
   }
  });

  rotText = (TextView) findViewById(R.id.textRot);
  rotBarRed = (SeekBar) findViewById(R.id.rotbarred);
  rotBarGreen = (SeekBar) findViewById(R.id.rotbargreen);
  rotBarBlue = (SeekBar) findViewById(R.id.rotbarblue);
  rotBarRed.setOnSeekBarChangeListener(seekBarChangeListener);
  rotBarGreen.setOnSeekBarChangeListener(seekBarChangeListener);
  rotBarBlue.setOnSeekBarChangeListener(seekBarChangeListener);

 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);

  if (resultCode == RESULT_OK) {
   switch (requestCode) {
   case RQS_IMAGE1:
    source = data.getData();

    try {
     bitmapMaster = BitmapFactory
       .decodeStream(getContentResolver().openInputStream(
         source));

     rotBarRed.setProgress(0);
     rotBarGreen.setProgress(0);
     rotBarBlue.setProgress(0);

     loadBitmapRotate();

    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }

    break;
   }
  }
 }

 OnSeekBarChangeListener seekBarChangeListener = new OnSeekBarChangeListener() {

  @Override
  public void onProgressChanged(SeekBar seekBar, int progress,
    boolean fromUser) {
   // TODO Auto-generated method stub

  }

  @Override
  public void onStartTrackingTouch(SeekBar seekBar) {
   // TODO Auto-generated method stub

  }

  @Override
  public void onStopTrackingTouch(SeekBar seekBar) {
   loadBitmapRotate();
  }
 };

 private void loadBitmapRotate() {
  if (bitmapMaster != null) {

   float rotRed = (float) rotBarRed.getProgress();
   float rotGreen = (float) rotBarGreen.getProgress();
   float rotBlue = (float) rotBarBlue.getProgress();

   rotText.setText("setRotate: " + String.valueOf(rotRed) + ", "
     + String.valueOf(rotGreen) + ", " + String.valueOf(rotBlue));

   Bitmap bitmapColorScaled = updateRot(bitmapMaster, rotRed,
     rotGreen, rotBlue);

   imageResult.setImageBitmap(bitmapColorScaled);
  }
 }

 private Bitmap updateRot(Bitmap src, float degreesRed, float degreesGreen,
   float degreesBlue) {

  int w = src.getWidth();
  int h = src.getHeight();

  Bitmap bitmapResult = Bitmap
    .createBitmap(w, h, Bitmap.Config.ARGB_8888);
  Canvas canvasResult = new Canvas(bitmapResult);
  Paint paint = new Paint();

  ColorMatrix colorMatrixRed = new ColorMatrix();
  colorMatrixRed.setRotate(0, degreesRed);
  ColorMatrix colorMatrixGreen = new ColorMatrix();
  colorMatrixGreen.setRotate(1, degreesGreen);
  ColorMatrix colorMatrixBlue = new ColorMatrix();
  colorMatrixBlue.setRotate(2, degreesBlue);
  ColorMatrix colorMatrixConcat = new ColorMatrix();
  colorMatrixConcat.setConcat(colorMatrixRed, colorMatrixGreen);
  colorMatrixConcat.setConcat(colorMatrixConcat, colorMatrixBlue);

  ColorMatrixColorFilter filter = new ColorMatrixColorFilter(
    colorMatrixConcat);
  paint.setColorFilter(filter);
  canvasResult.drawBitmap(src, 0, 0, paint);

  return bitmapResult;
 }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <Button
        android:id="@+id/loadimage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Load Image 1" />

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

            <ImageView
                android:id="@+id/result"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:adjustViewBounds="true"
                android:background="@android:color/background_dark"
                android:scaleType="centerInside" />

            <TextView
                android:id="@+id/textRot"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="ColorMatrix Rotate" />

            <SeekBar
                android:id="@+id/rotbarred"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:max="360"
                android:progress="0" />
            <SeekBar
                android:id="@+id/rotbargreen"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:max="360"
                android:progress="0" />
            <SeekBar
                android:id="@+id/rotbarblue"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:max="360"
                android:progress="0" />
        </LinearLayout>
    </ScrollView>

</LinearLayout>

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more: Something about processing images in Android