alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Android example source code file (ViewAnimator.java)

This example Android source code file (ViewAnimator.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, animation, attributeset, content, framelayout, override, typedarray, ui, util, utilities, view, viewanimator

The ViewAnimator.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.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;

/**
 * Base class for a {@link FrameLayout} container that will perform animations
 * when switching between its views.
 *
 * @attr ref android.R.styleable#ViewAnimator_inAnimation
 * @attr ref android.R.styleable#ViewAnimator_outAnimation
 */
public class ViewAnimator extends FrameLayout {

    int mWhichChild = 0;
    boolean mFirstTime = true;
    boolean mAnimateFirstTime = true;

    Animation mInAnimation;
    Animation mOutAnimation;

    public ViewAnimator(Context context) {
        super(context);
        initViewAnimator(context, null);
    }

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

        TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.ViewAnimator);
        int resource = a.getResourceId(com.android.internal.R.styleable.ViewAnimator_inAnimation, 0);
        if (resource > 0) {
            setInAnimation(context, resource);
        }

        resource = a.getResourceId(com.android.internal.R.styleable.ViewAnimator_outAnimation, 0);
        if (resource > 0) {
            setOutAnimation(context, resource);
        }
        a.recycle();

        initViewAnimator(context, attrs);
    }

    /**
     * Initialize this {@link ViewAnimator}, possibly setting
     * {@link #setMeasureAllChildren(boolean)} based on {@link FrameLayout} flags.
     */
    private void initViewAnimator(Context context, AttributeSet attrs) {
        if (attrs == null) {
            // For compatibility, always measure children when undefined.
            mMeasureAllChildren = true;
            return;
        }

        // For compatibility, default to measure children, but allow XML
        // attribute to override.
        final TypedArray a = context.obtainStyledAttributes(attrs,
                com.android.internal.R.styleable.FrameLayout);
        final boolean measureAllChildren = a.getBoolean(
                com.android.internal.R.styleable.FrameLayout_measureAllChildren, true);
        setMeasureAllChildren(measureAllChildren);
        a.recycle();
    }
    
    /**
     * Sets which child view will be displayed.
     * 
     * @param whichChild the index of the child view to display
     */
    public void setDisplayedChild(int whichChild) {
        mWhichChild = whichChild;
        if (whichChild >= getChildCount()) {
            mWhichChild = 0;
        } else if (whichChild < 0) {
            mWhichChild = getChildCount() - 1;
        }
        boolean hasFocus = getFocusedChild() != null;
        // This will clear old focus if we had it
        showOnly(mWhichChild);
        if (hasFocus) {
            // Try to retake focus if we had it
            requestFocus(FOCUS_FORWARD);
        }
    }
    
    /**
     * Returns the index of the currently displayed child view.
     */
    public int getDisplayedChild() {
        return mWhichChild;
    }
    
    /**
     * Manually shows the next child.
     */
    public void showNext() {
        setDisplayedChild(mWhichChild + 1);
    }

    /**
     * Manually shows the previous child.
     */
    public void showPrevious() {
        setDisplayedChild(mWhichChild - 1);
    }

    /**
     * Shows only the specified child. The other displays Views exit the screen
     * with the {@link #getOutAnimation() out animation} and the specified child
     * enters the screen with the {@link #getInAnimation() in animation}.
     *
     * @param childIndex The index of the child to be shown.
     */
    void showOnly(int childIndex) {
        final int count = getChildCount();
        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            final boolean checkForFirst = (!mFirstTime || mAnimateFirstTime);
            if (i == childIndex) {
                if (checkForFirst && mInAnimation != null) {
                    child.startAnimation(mInAnimation);
                }
                child.setVisibility(View.VISIBLE);
                mFirstTime = false;
            } else {
                if (checkForFirst && mOutAnimation != null && child.getVisibility() == View.VISIBLE) {
                    child.startAnimation(mOutAnimation);
                } else if (child.getAnimation() == mInAnimation)
                    child.clearAnimation();
                child.setVisibility(View.GONE);
            }
        }
    }

    @Override
    public void addView(View child, int index, ViewGroup.LayoutParams params) {
        super.addView(child, index, params);
        if (getChildCount() == 1) {
            child.setVisibility(View.VISIBLE);
        } else {
            child.setVisibility(View.GONE);
        }
    }

    @Override
    public void removeAllViews() {
        super.removeAllViews();
        mWhichChild = 0;
        mFirstTime = true;
    }

    @Override
    public void removeView(View view) {
        final int index = indexOfChild(view);
        if (index >= 0) {
            removeViewAt(index);
        }
    }

    @Override
    public void removeViewAt(int index) {
        super.removeViewAt(index);
        final int childCount = getChildCount();
        if (childCount == 0) {
            mWhichChild = 0;
            mFirstTime = true;
        } else if (mWhichChild >= childCount) {
            // Displayed is above child count, so float down to top of stack
            setDisplayedChild(childCount - 1);
        } else if (mWhichChild == index) {
            // Displayed was removed, so show the new child living in its place
            setDisplayedChild(mWhichChild);
        }
    }

    public void removeViewInLayout(View view) {
        removeView(view);
    }

    public void removeViews(int start, int count) {
        super.removeViews(start, count);
        if (getChildCount() == 0) {
            mWhichChild = 0;
            mFirstTime = true;
        } else if (mWhichChild >= start && mWhichChild < start + count) {
            // Try showing new displayed child, wrapping if needed
            setDisplayedChild(mWhichChild);
        }
    }

    public void removeViewsInLayout(int start, int count) {
        removeViews(start, count);
    }

    /**
     * Returns the View corresponding to the currently displayed child.
     *
     * @return The View currently displayed.
     *
     * @see #getDisplayedChild()
     */
    public View getCurrentView() {
        return getChildAt(mWhichChild);
    }

    /**
     * Returns the current animation used to animate a View that enters the screen.
     *
     * @return An Animation or null if none is set.
     *
     * @see #setInAnimation(android.view.animation.Animation)
     * @see #setInAnimation(android.content.Context, int)
     */
    public Animation getInAnimation() {
        return mInAnimation;
    }

    /**
     * Specifies the animation used to animate a View that enters the screen.
     *
     * @param inAnimation The animation started when a View enters the screen.
     *
     * @see #getInAnimation()
     * @see #setInAnimation(android.content.Context, int)
     */
    public void setInAnimation(Animation inAnimation) {
        mInAnimation = inAnimation;
    }

    /**
     * Returns the current animation used to animate a View that exits the screen.
     *
     * @return An Animation or null if none is set.
     *
     * @see #setOutAnimation(android.view.animation.Animation)
     * @see #setOutAnimation(android.content.Context, int)
     */
    public Animation getOutAnimation() {
        return mOutAnimation;
    }

    /**
     * Specifies the animation used to animate a View that exit the screen.
     *
     * @param outAnimation The animation started when a View exit the screen.
     *
     * @see #getOutAnimation()
     * @see #setOutAnimation(android.content.Context, int)
     */
    public void setOutAnimation(Animation outAnimation) {
        mOutAnimation = outAnimation;
    }

    /**
     * Specifies the animation used to animate a View that enters the screen.
     *
     * @param context The application's environment.
     * @param resourceID The resource id of the animation.
     *
     * @see #getInAnimation()
     * @see #setInAnimation(android.view.animation.Animation)
     */
    public void setInAnimation(Context context, int resourceID) {
        setInAnimation(AnimationUtils.loadAnimation(context, resourceID));
    }

    /**
     * Specifies the animation used to animate a View that exit the screen.
     *
     * @param context The application's environment.
     * @param resourceID The resource id of the animation.
     *
     * @see #getOutAnimation()
     * @see #setOutAnimation(android.view.animation.Animation)
     */
    public void setOutAnimation(Context context, int resourceID) {
        setOutAnimation(AnimationUtils.loadAnimation(context, resourceID));
    }

    /**
     * Indicates whether the current View should be animated the first time
     * the ViewAnimation is displayed.
     *
     * @param animate True to animate the current View the first time it is displayed,
     *                false otherwise.
     */
    public void setAnimateFirstView(boolean animate) {
        mAnimateFirstTime = animate;
    }

    @Override
    public int getBaseline() {
        return (getCurrentView() != null) ? getCurrentView().getBaseline() : super.getBaseline();
    }
}

Other Android examples (source code examples)

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

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.