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Android example source code file (ZoomButton.java)

This example Android source code file (ZoomButton.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, content, handler, imagebutton, keyevent, onlongclicklistener, os, override, runnable, ui, util, view, zoombutton

The ZoomButton.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.widget;

import android.content.Context;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnLongClickListener;

public class ZoomButton extends ImageButton implements OnLongClickListener {

    private final Handler mHandler;
    private final Runnable mRunnable = new Runnable() {
        public void run() {
            if ((mOnClickListener != null) && mIsInLongpress && isEnabled()) {
                mOnClickListener.onClick(ZoomButton.this);
                mHandler.postDelayed(this, mZoomSpeed);
            }
        }
    };
    
    private long mZoomSpeed = 1000;
    private boolean mIsInLongpress;
    
    public ZoomButton(Context context) {
        this(context, null);
    }

    public ZoomButton(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
    
    public ZoomButton(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mHandler = new Handler();
        setOnLongClickListener(this);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if ((event.getAction() == MotionEvent.ACTION_CANCEL)
                || (event.getAction() == MotionEvent.ACTION_UP)) {
            mIsInLongpress = false;
        }
        return super.onTouchEvent(event);
    }
        
    public void setZoomSpeed(long speed) {
        mZoomSpeed = speed;
    }

    public boolean onLongClick(View v) {
        mIsInLongpress = true;
        mHandler.post(mRunnable);
        return true;
    }
        
    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        mIsInLongpress = false;
        return super.onKeyUp(keyCode, event);
    }
    
    @Override
    public void setEnabled(boolean enabled) {
        if (!enabled) {
            
            /* If we're being disabled reset the state back to unpressed
             * as disabled views don't get events and therefore we won't
             * get the up event to reset the state.
             */
            setPressed(false);
        }
        super.setEnabled(enabled);
    }
    
    @Override
    public boolean dispatchUnhandledMove(View focused, int direction) {
        clearFocus();
        return super.dispatchUnhandledMove(focused, direction);
    }
}

Other Android examples (source code examples)

Here is a short list of links related to this Android ZoomButton.java source code file:

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