Android-er: ColorMatrix.setConcat() to combine ColorMatrixes

Monday, September 30, 2013

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().

ColorMatrix.setConcat() to combine ColorMatrixs

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>