Android example source code file (InsetDrawable.java)

This example Android source code file (InsetDrawable.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, attributeset, constantstate, content, drawable, insetdrawable, insetdrawable_drawable, insetdrawable_insettop, insetstate, io, ioexception, no, override, rect, resources, runnable, util, utilities, utils, xmlpullparserexception

The InsetDrawable.java Android example source code

/*
 * Copyright (C) 2008 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;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.*;
import android.util.AttributeSet;
import android.util.Log;

import java.io.IOException;

/**
 * A Drawable that insets another Drawable by a specified distance.
 * This is used when a View needs a background that is smaller than
 * the View's actual bounds.
 *
 * <p>It can be defined in an XML file with the <inset> element.

 *
 * @attr ref android.R.styleable#InsetDrawable_visible
 * @attr ref android.R.styleable#InsetDrawable_drawable
 * @attr ref android.R.styleable#InsetDrawable_insetLeft
 * @attr ref android.R.styleable#InsetDrawable_insetRight
 * @attr ref android.R.styleable#InsetDrawable_insetTop
 * @attr ref android.R.styleable#InsetDrawable_insetBottom
 */
public class InsetDrawable extends Drawable implements Drawable.Callback
{
    // Most of this is copied from ScaleDrawable.
    private InsetState mInsetState;
    private final Rect mTmpRect = new Rect();
    private boolean mMutated;

    /*package*/ InsetDrawable() {
        this(null, null);
    }

    public InsetDrawable(Drawable drawable, int inset) {
        this(drawable, inset, inset, inset, inset);
    }

    public InsetDrawable(Drawable drawable, int insetLeft, int insetTop,
                         int insetRight, int insetBottom) {
        this(null, null);
        
        mInsetState.mDrawable = drawable;
        mInsetState.mInsetLeft = insetLeft;
        mInsetState.mInsetTop = insetTop;
        mInsetState.mInsetRight = insetRight;
        mInsetState.mInsetBottom = insetBottom;
        
        if (drawable != null) {
            drawable.setCallback(this);
        }
    }
    
    @Override public void inflate(Resources r, XmlPullParser parser,
                                  AttributeSet attrs)
    throws XmlPullParserException, IOException {
        int type;
        
        TypedArray a = r.obtainAttributes(attrs,
                com.android.internal.R.styleable.InsetDrawable);

        super.inflateWithAttributes(r, parser, a,
                com.android.internal.R.styleable.InsetDrawable_visible);

        int drawableRes = a.getResourceId(com.android.internal.R.styleable.
                                    InsetDrawable_drawable, 0);

        int inLeft = a.getDimensionPixelOffset(com.android.internal.R.styleable.
                                    InsetDrawable_insetLeft, 0);
        int inTop = a.getDimensionPixelOffset(com.android.internal.R.styleable.
                                    InsetDrawable_insetTop, 0);
        int inRight = a.getDimensionPixelOffset(com.android.internal.R.styleable.
                                    InsetDrawable_insetRight, 0);
        int inBottom = a.getDimensionPixelOffset(com.android.internal.R.styleable.
                                    InsetDrawable_insetBottom, 0);

        a.recycle();

        Drawable dr;
        if (drawableRes != 0) {
            dr = r.getDrawable(drawableRes);
        } else {
            while ((type=parser.next()) == XmlPullParser.TEXT) {
            }
            if (type != XmlPullParser.START_TAG) {
                throw new XmlPullParserException(
                        parser.getPositionDescription()
                        + ": <inset> tag requires a 'drawable' attribute or "
                        + "child tag defining a drawable");
            }
            dr = Drawable.createFromXmlInner(r, parser, attrs);
        }

        if (dr == null) {
            Log.w("drawable", "No drawable specified for <inset>");
        }

        mInsetState.mDrawable = dr;
        mInsetState.mInsetLeft = inLeft;
        mInsetState.mInsetRight = inRight;
        mInsetState.mInsetTop = inTop;
        mInsetState.mInsetBottom = inBottom;

        if (dr != null) {
            dr.setCallback(this);
        }
    }

    // overrides from Drawable.Callback

    public void invalidateDrawable(Drawable who) {
        if (mCallback != null) {
            mCallback.invalidateDrawable(this);
        }
    }

    public void scheduleDrawable(Drawable who, Runnable what, long when) {
        if (mCallback != null) {
            mCallback.scheduleDrawable(this, what, when);
        }
    }

    public void unscheduleDrawable(Drawable who, Runnable what) {
        if (mCallback != null) {
            mCallback.unscheduleDrawable(this, what);
        }
    }

    // overrides from Drawable

    @Override
    public void draw(Canvas canvas) {
        mInsetState.mDrawable.draw(canvas);
    }

    @Override
    public int getChangingConfigurations() {
        return super.getChangingConfigurations()
                | mInsetState.mChangingConfigurations
                | mInsetState.mDrawable.getChangingConfigurations();
    }
    
    @Override
    public boolean getPadding(Rect padding) {
        boolean pad = mInsetState.mDrawable.getPadding(padding);

        padding.left += mInsetState.mInsetLeft;
        padding.right += mInsetState.mInsetRight;
        padding.top += mInsetState.mInsetTop;
        padding.bottom += mInsetState.mInsetBottom;

        if (pad || (mInsetState.mInsetLeft | mInsetState.mInsetRight | 
                    mInsetState.mInsetTop | mInsetState.mInsetBottom) != 0) {
            return true;
        } else {
            return false;
        }
    }

    @Override
    public boolean setVisible(boolean visible, boolean restart) {
        mInsetState.mDrawable.setVisible(visible, restart);
        return super.setVisible(visible, restart);
    }

    @Override
    public void setAlpha(int alpha) {
        mInsetState.mDrawable.setAlpha(alpha);
    }
    
    @Override
    public void setColorFilter(ColorFilter cf) {
        mInsetState.mDrawable.setColorFilter(cf);
    }
    
    @Override
    public int getOpacity() {
        return mInsetState.mDrawable.getOpacity();
    }
    
    @Override
    public boolean isStateful() {
        return mInsetState.mDrawable.isStateful();
    }

    @Override
    protected boolean onStateChange(int[] state) {
        boolean changed = mInsetState.mDrawable.setState(state);
        onBoundsChange(getBounds());
        return changed;
    }
    
    @Override
    protected void onBoundsChange(Rect bounds) {
        final Rect r = mTmpRect;
        r.set(bounds);

        r.left += mInsetState.mInsetLeft;
        r.top += mInsetState.mInsetTop;
        r.right -= mInsetState.mInsetRight;
        r.bottom -= mInsetState.mInsetBottom;

        mInsetState.mDrawable.setBounds(r.left, r.top, r.right, r.bottom);
    }

    @Override
    public int getIntrinsicWidth() {
        return mInsetState.mDrawable.getIntrinsicWidth();
    }

    @Override
    public int getIntrinsicHeight() {
        return mInsetState.mDrawable.getIntrinsicHeight();
    }

    @Override
    public ConstantState getConstantState() {
        if (mInsetState.canConstantState()) {
            mInsetState.mChangingConfigurations = super.getChangingConfigurations();
            return mInsetState;
        }
        return null;
    }

    @Override
    public Drawable mutate() {
        if (!mMutated && super.mutate() == this) {
            mInsetState.mDrawable.mutate();
            mMutated = true;
        }
        return this;
    }

    final static class InsetState extends ConstantState {
        Drawable mDrawable;
        int mChangingConfigurations;

        int mInsetLeft;
        int mInsetTop;
        int mInsetRight;
        int mInsetBottom;

        boolean mCheckedConstantState;
        boolean mCanConstantState;

        InsetState(InsetState orig, InsetDrawable owner, Resources res) {
            if (orig != null) {
                if (res != null) {
                    mDrawable = orig.mDrawable.getConstantState().newDrawable(res);
                } else {
                    mDrawable = orig.mDrawable.getConstantState().newDrawable();
                }
                mDrawable.setCallback(owner);
                mInsetLeft = orig.mInsetLeft;
                mInsetTop = orig.mInsetTop;
                mInsetRight = orig.mInsetRight;
                mInsetBottom = orig.mInsetBottom;
                mCheckedConstantState = mCanConstantState = true;
            }
        }

        @Override
        public Drawable newDrawable() {
            return new InsetDrawable(this, null);
        }
        
        @Override
        public Drawable newDrawable(Resources res) {
            return new InsetDrawable(this, res);
        }
        
        @Override
        public int getChangingConfigurations() {
            return mChangingConfigurations;
        }

        boolean canConstantState() {
            if (!mCheckedConstantState) {
                mCanConstantState = mDrawable.getConstantState() != null;
                mCheckedConstantState = true;
            }

            return mCanConstantState;
        }
    }

    private InsetDrawable(InsetState state, Resources res) {
        mInsetState = new InsetState(state, this, res);
    }
}