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Shape Drawing Example in Android


Posted by Sushant on July 4, 2012, filed in: Android Game Programming, ANDROID TUTORIAL

This example shows how you can use shapedrawable class to draw different shapes in android.

Algorithm:

1.) Create a new project by File-> New -> Android Project name it ShapeDrawingExample.

2.) Create and write following into src/GraphicsActivity.java:

package com.example.ShapeDrawingExample;

import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.view.ViewGroup;
class GraphicsActivity extends Activity {
     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);
     }
 }

3.) Create and write following into src/PictureLayout.java:

package com.example.ShapeDrawingExample;
import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Picture;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewParent;
public 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();
     }
    @SuppressWarnings("unused")
         @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());
            }
         }
     }
 }

4.) Run for output.

Steps:

1.) Create a project named ShapeDrawingExample and set the information as stated in the image.

Build Target: Android 4.0
Application Name: ShapeDrawingExample
Package Name: com. example. ShapeDrawingExample
Activity Name: ShapeDrawingExampleActivity
Min SDK Version: 14

2.) Open ShapeDrawingExampleActivity.java file and write following code there:

package com.example.ShapeDrawingExample;

import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.BitmapShader;
 import android.graphics.Canvas;
 import android.graphics.ComposePathEffect;
 import android.graphics.CornerPathEffect;
 import android.graphics.DiscretePathEffect;
 import android.graphics.LinearGradient;
 import android.graphics.Paint;
 import android.graphics.Path;
 import android.graphics.PathEffect;
 import android.graphics.RectF;
 import android.graphics.Shader;
 import android.graphics.SweepGradient;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.ShapeDrawable;
 import android.graphics.drawable.shapes.ArcShape;
 import android.graphics.drawable.shapes.OvalShape;
 import android.graphics.drawable.shapes.PathShape;
 import android.graphics.drawable.shapes.RectShape;
 import android.graphics.drawable.shapes.RoundRectShape;
 import android.graphics.drawable.shapes.Shape;
 import android.os.Bundle;
 import android.view.View;
public class ShapeDrawingExampleActivity extends GraphicsActivity {
    @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(new SampleView(this));
     }
    private static class SampleView extends View {
         private ShapeDrawable[] mDrawables;
        private static Shader makeSweep() {
             return new SweepGradient(150, 25,
                 new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0xFFFF0000 },
                 null);
         }
        private static Shader makeLinear() {
             return new LinearGradient(0, 0, 50, 50,
                               new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF },
                               null, Shader.TileMode.MIRROR);
         }
        private static Shader makeTiling() {
             int[] pixels = new int[] { 0xFF00FF00, 0xFF0000FF,0xFFFF0000, 0};
             Bitmap bm = Bitmap.createBitmap(pixels, 2, 2,
                                             Bitmap.Config.ARGB_8888);
            return new BitmapShader(bm, Shader.TileMode.REPEAT,
                                         Shader.TileMode.REPEAT);
         }
        private static class MyShapeDrawable extends ShapeDrawable {
             private Paint mStrokePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            public MyShapeDrawable(Shape s) {
                 super(s);
                 mStrokePaint.setStyle(Paint.Style.STROKE);
             }
            public Paint getStrokePaint() {
                 return mStrokePaint;
             }
            @Override protected void onDraw(Shape s, Canvas c, Paint p) {
                 s.draw(c, p);
                 s.draw(c, mStrokePaint);
             }
         }
        public SampleView(Context context) {
             super(context);
             setFocusable(true);
            float[] outerR = new float[] { 12, 12, 12, 12, 0, 0, 0, 0 };
             RectF   inset = new RectF(6, 6, 6, 6);
             float[] innerR = new float[] { 12, 12, 0, 0, 12, 12, 0, 0 };
            Path path = new Path();
             path.moveTo(50, 0);
             path.lineTo(0, 50);
             path.lineTo(50, 100);
             path.lineTo(100, 50);
             path.close();
            mDrawables = new ShapeDrawable[7];
             mDrawables[0] = new ShapeDrawable(new RectShape());
             mDrawables[1] = new ShapeDrawable(new OvalShape());
             mDrawables[2] = new ShapeDrawable(new RoundRectShape(outerR, null,
                                                                  null));
             mDrawables[3] = new ShapeDrawable(new RoundRectShape(outerR, inset,
                                                                  null));
             mDrawables[4] = new ShapeDrawable(new RoundRectShape(outerR, inset,
                                                                  innerR));
             mDrawables[5] = new ShapeDrawable(new PathShape(path, 100, 100));
             mDrawables[6] = new MyShapeDrawable(new ArcShape(45, -270));
            mDrawables[0].getPaint().setColor(0xFF0000FF);
             mDrawables[1].getPaint().setColor(0xFF00FF00);
             mDrawables[2].getPaint().setColor(0xFFFF0000);
             mDrawables[3].getPaint().setShader(makeSweep());
             mDrawables[4].getPaint().setShader(makeLinear());
             mDrawables[5].getPaint().setShader(makeTiling());
             mDrawables[6].getPaint().setColor(0x88FF8844);
            PathEffect pe = new DiscretePathEffect(10, 4);
             PathEffect pe2 = new CornerPathEffect(4);
             mDrawables[3].getPaint().setPathEffect(
                                                 new ComposePathEffect(pe2, pe));
            MyShapeDrawable msd = (MyShapeDrawable)mDrawables[6];
             msd.getStrokePaint().setStrokeWidth(4);
         }
        @Override protected void onDraw(Canvas canvas) {
            int x = 10;
             int y = 10;
             int width = 300;
             int height = 50;
            for (Drawable dr : mDrawables) {
                 dr.setBounds(x, y, x + width, y + height);
                 dr.draw(canvas);
                 y += height + 5;
             }
         }
     }
 }

3.) Compile and build the project.

Output

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