Android example source code file (RoundRectShape.java)

This example Android source code file (RoundRectShape.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, arrayindexoutofboundsexception, clonenotsupportedexception, drawing, graphics, override, paint, path, rectf, roundrectshape, ui

The RoundRectShape.java Android example source code

/*
 * 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 android.graphics.drawable.shapes;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;

/**
 * Creates a rounded-corner rectangle. Optionally, an inset (rounded) rectangle
 * can be included (to make a sort of "O" shape). 
 * The rounded rectangle can be drawn to a Canvas with its own draw() method,
 * but more graphical control is available if you instead pass
 * the RoundRectShape to a {@link android.graphics.drawable.ShapeDrawable}.
 */
public class RoundRectShape extends RectShape {
    private float[] mOuterRadii;
    private RectF   mInset;
    private float[] mInnerRadii;
    
    private RectF mInnerRect;
    private Path  mPath;    // this is what we actually draw
    
    /**
     * RoundRectShape constructor.
     * Specifies an outer (round)rect and an optional inner (round)rect.
     *
     * @param outerRadii An array of 8 radius values, for the outer roundrect. 
     *                   The first two floats are for the 
     *                   top-left corner (remaining pairs correspond clockwise). 
     *                   For no rounded corners on the outer rectangle, 
     *                   pass null.
     * @param inset      A RectF that specifies the distance from the inner 
     *                   rect to each side of the outer rect. 
     *                   For no inner, pass null.
     * @param innerRadii An array of 8 radius values, for the inner roundrect.
     *                   The first two floats are for the 
     *                   top-left corner (remaining pairs correspond clockwise). 
     *                   For no rounded corners on the inner rectangle, 
     *                   pass null.
     *                   If inset parameter is null, this parameter is ignored. 
     */
    public RoundRectShape(float[] outerRadii, RectF inset,
                          float[] innerRadii) {
        if (outerRadii.length < 8) {
            throw new ArrayIndexOutOfBoundsException(
                                        "outer radii must have >= 8 values");
        }
        if (innerRadii != null && innerRadii.length < 8) {
            throw new ArrayIndexOutOfBoundsException(
                                        "inner radii must have >= 8 values");
        }
        mOuterRadii = outerRadii;
        mInset = inset;
        mInnerRadii = innerRadii;
        
        if (inset != null) {
            mInnerRect = new RectF();
        }
        mPath = new Path();
    }
    
    @Override
    public void draw(Canvas canvas, Paint paint) {
        canvas.drawPath(mPath, paint);
    }
    
    @Override
    protected void onResize(float w, float h) {
        super.onResize(w, h);
        
        RectF r = rect();
        mPath.reset();

        if (mOuterRadii != null) {
            mPath.addRoundRect(r, mOuterRadii, Path.Direction.CW);
        } else {
            mPath.addRect(r, Path.Direction.CW);
        }
        if (mInnerRect != null) {
            mInnerRect.set(r.left + mInset.left, r.top + mInset.top,
                           r.right - mInset.right, r.bottom - mInset.bottom);
            if (mInnerRect.width() < w && mInnerRect.height() < h) {
                if (mInnerRadii != null) {
                    mPath.addRoundRect(mInnerRect, mInnerRadii,
                                       Path.Direction.CCW);
                } else {
                    mPath.addRect(mInnerRect, Path.Direction.CCW);
                }
            }
        }
    }

    @Override
    public RoundRectShape clone() throws CloneNotSupportedException {
        RoundRectShape shape = (RoundRectShape) super.clone();
        shape.mOuterRadii = mOuterRadii.clone();
        shape.mInnerRadii = mInnerRadii.clone();
        shape.mInset = new RectF(mInset);
        shape.mInnerRect = new RectF(mInnerRect);
        shape.mPath = new Path(mPath);
        return shape;
    }
}