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Android example source code file (ViewFlipper.java)

This example Android source code file (ViewFlipper.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, broadcastreceiver, content, default_interval, flip_msg, handler, intentfilter, logd, message, os, override, string, tag, util, utilities, utils, viewanimator, viewflipper, visible

The ViewFlipper.java Android example source code

/*
 * Copyright (C) 2006 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.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.TypedArray;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.RemoteViews.RemoteView;

/**
 * Simple {@link ViewAnimator} that will animate between two or more views
 * that have been added to it.  Only one child is shown at a time.  If
 * requested, can automatically flip between each child at a regular interval.
 *
 * @attr ref android.R.styleable#ViewFlipper_flipInterval
 * @attr ref android.R.styleable#ViewFlipper_autoStart
 */
@RemoteView
public class ViewFlipper extends ViewAnimator {
    private static final String TAG = "ViewFlipper";
    private static final boolean LOGD = false;

    private static final int DEFAULT_INTERVAL = 3000;

    private int mFlipInterval = DEFAULT_INTERVAL;
    private boolean mAutoStart = false;

    private boolean mRunning = false;
    private boolean mStarted = false;
    private boolean mVisible = false;
    private boolean mUserPresent = true;

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

    public ViewFlipper(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray a = context.obtainStyledAttributes(attrs,
                com.android.internal.R.styleable.ViewFlipper);
        mFlipInterval = a.getInt(
                com.android.internal.R.styleable.ViewFlipper_flipInterval, DEFAULT_INTERVAL);
        mAutoStart = a.getBoolean(
                com.android.internal.R.styleable.ViewFlipper_autoStart, false);
        a.recycle();
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            final String action = intent.getAction();
            if (Intent.ACTION_SCREEN_OFF.equals(action)) {
                mUserPresent = false;
                updateRunning();
            } else if (Intent.ACTION_USER_PRESENT.equals(action)) {
                mUserPresent = true;
                updateRunning();
            }
        }
    };

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();

        // Listen for broadcasts related to user-presence
        final IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);
        getContext().registerReceiver(mReceiver, filter);

        if (mAutoStart) {
            // Automatically start when requested
            startFlipping();
        }
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        mVisible = false;

        getContext().unregisterReceiver(mReceiver);
        updateRunning();
    }

    @Override
    protected void onWindowVisibilityChanged(int visibility) {
        super.onWindowVisibilityChanged(visibility);
        mVisible = visibility == VISIBLE;
        updateRunning();
    }

    /**
     * How long to wait before flipping to the next view
     *
     * @param milliseconds
     *            time in milliseconds
     */
    @android.view.RemotableViewMethod
    public void setFlipInterval(int milliseconds) {
        mFlipInterval = milliseconds;
    }

    /**
     * Start a timer to cycle through child views
     */
    public void startFlipping() {
        mStarted = true;
        updateRunning();
    }

    /**
     * No more flips
     */
    public void stopFlipping() {
        mStarted = false;
        updateRunning();
    }

    /**
     * Internal method to start or stop dispatching flip {@link Message} based
     * on {@link #mRunning} and {@link #mVisible} state.
     */
    private void updateRunning() {
        boolean running = mVisible && mStarted && mUserPresent;
        if (running != mRunning) {
            if (running) {
                showOnly(mWhichChild);
                Message msg = mHandler.obtainMessage(FLIP_MSG);
                mHandler.sendMessageDelayed(msg, mFlipInterval);
            } else {
                mHandler.removeMessages(FLIP_MSG);
            }
            mRunning = running;
        }
        if (LOGD) {
            Log.d(TAG, "updateRunning() mVisible=" + mVisible + ", mStarted=" + mStarted
                    + ", mUserPresent=" + mUserPresent + ", mRunning=" + mRunning);
        }
    }

    /**
     * Returns true if the child views are flipping.
     */
    public boolean isFlipping() {
        return mStarted;
    }

    /**
     * Set if this view automatically calls {@link #startFlipping()} when it
     * becomes attached to a window.
     */
    public void setAutoStart(boolean autoStart) {
        mAutoStart = autoStart;
    }

    /**
     * Returns true if this view automatically calls {@link #startFlipping()}
     * when it becomes attached to a window.
     */
    public boolean isAutoStart() {
        return mAutoStart;
    }

    private final int FLIP_MSG = 1;

    private final Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == FLIP_MSG) {
                if (mRunning) {
                    showNext();
                    msg = obtainMessage(FLIP_MSG);
                    sendMessageDelayed(msg, mFlipInterval);
                }
            }
        }
    };
}

Other Android examples (source code examples)

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

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