Using GradientDrawable : Drawable « 2D Graphics « Android

1. Android
2. 2D Graphics
3. Drawable

Using GradientDrawable

  
/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package app.test;

import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.GradientDrawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;

public class Test extends GraphicsActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new SampleView(this));
  }

  private static class SampleView extends View {
    private Path mPath;
    private Paint mPaint;
    private Rect mRect;
    private GradientDrawable mDrawable;

    public SampleView(Context context) {
      super(context);
      setFocusable(true);

      mPath = new Path();
      mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
      mRect = new Rect(0, 0, 120, 120);

      mDrawable = new GradientDrawable(
          GradientDrawable.Orientation.TL_BR, new int[] { 0xFFFF0000,
              0xFF00FF00, 0xFF0000FF });
      mDrawable.setShape(GradientDrawable.RECTANGLE);
      mDrawable.setGradientRadius((float) (Math.sqrt(2) * 60));
    }

    static void setCornerRadii(GradientDrawable drawable, float r0,
        float r1, float r2, float r3) {
      drawable.setCornerRadii(new float[] { r0, r0, r1, r1, r2, r2, r3,
          r3 });
    }

    @Override
    protected void onDraw(Canvas canvas) {

      mDrawable.setBounds(mRect);

      float r = 16;

      canvas.save();
      canvas.translate(10, 10);
      mDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);
      setCornerRadii(mDrawable, r, r, 0, 0);
      mDrawable.draw(canvas);
      canvas.restore();

      canvas.save();
      canvas.translate(10 + mRect.width() + 10, 10);
      mDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);
      setCornerRadii(mDrawable, 0, 0, r, r);
      mDrawable.draw(canvas);
      canvas.restore();

      canvas.translate(0, mRect.height() + 10);

      canvas.save();
      canvas.translate(10, 10);
      mDrawable.setGradientType(GradientDrawable.SWEEP_GRADIENT);
      setCornerRadii(mDrawable, 0, r, r, 0);
      mDrawable.draw(canvas);
      canvas.restore();

      canvas.save();
      canvas.translate(10 + mRect.width() + 10, 10);
      mDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);
      setCornerRadii(mDrawable, r, 0, 0, r);
      mDrawable.draw(canvas);
      canvas.restore();

      canvas.translate(0, mRect.height() + 10);

      canvas.save();
      canvas.translate(10, 10);
      mDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);
      setCornerRadii(mDrawable, r, 0, r, 0);
      mDrawable.draw(canvas);
      canvas.restore();

      canvas.save();
      canvas.translate(10 + mRect.width() + 10, 10);
      mDrawable.setGradientType(GradientDrawable.SWEEP_GRADIENT);
      setCornerRadii(mDrawable, 0, r, 0, r);
      mDrawable.draw(canvas);
      canvas.restore();
    }
  }
}

class GraphicsActivity extends Activity {
  // set to true to test Picture
  private static final boolean TEST_PICTURE = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  }

  @Override
  public void setContentView(View view) {
    if (TEST_PICTURE) {
      ViewGroup vg = new PictureLayout(this);
      vg.addView(view);
      view = vg;
    }

    super.setContentView(view);
  }
}

class PictureLayout extends ViewGroup {
  private final Picture mPicture = new Picture();

  public PictureLayout(Context context) {
    super(context);
  }

  public PictureLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  @Override
  public void addView(View child) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child);
  }

  @Override
  public void addView(View child, int index) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index);
  }

  @Override
  public void addView(View child, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, params);
  }

  @Override
  public void addView(View child, int index, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index, params);
  }

  @Override
  protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.MATCH_PARENT,
        LayoutParams.MATCH_PARENT);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int count = getChildCount();

    int maxHeight = 0;
    int maxWidth = 0;

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
      }
    }

    maxWidth += getPaddingLeft() + getPaddingRight();
    maxHeight += getPaddingTop() + getPaddingBottom();

    Drawable drawable = getBackground();
    if (drawable != null) {
      maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
      maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
    }

    setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
        resolveSize(maxHeight, heightMeasureSpec));
  }

  private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
      float sy) {
    canvas.save();
    canvas.translate(x, y);
    canvas.clipRect(0, 0, w, h);
    canvas.scale(0.5f, 0.5f);
    canvas.scale(sx, sy, w, h);
    canvas.drawPicture(mPicture);
    canvas.restore();
  }

  @Override
  protected void dispatchDraw(Canvas canvas) {
    super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
    mPicture.endRecording();

    int x = getWidth() / 2;
    int y = getHeight() / 2;

    if (false) {
      canvas.drawPicture(mPicture);
    } else {
      drawPict(canvas, 0, 0, x, y, 1, 1);
      drawPict(canvas, x, 0, x, y, -1, 1);
      drawPict(canvas, 0, y, x, y, 1, -1);
      drawPict(canvas, x, y, x, y, -1, -1);
    }
  }

  @Override
  public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
    location[0] = getLeft();
    location[1] = getTop();
    dirty.set(0, 0, getWidth(), getHeight());
    return getParent();
  }

  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = super.getChildCount();

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        final int childLeft = getPaddingLeft();
        final int childTop = getPaddingTop();
        child.layout(childLeft, childTop,
            childLeft + child.getMeasuredWidth(),
            childTop + child.getMeasuredHeight());

      }
    }
  }
}

   
    
  

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