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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.widget;
     18 
     19 import android.annotation.Widget;
     20 import android.content.Context;
     21 import android.util.AttributeSet;
     22 import android.view.LayoutInflater;
     23 import android.view.MotionEvent;
     24 import android.view.View;
     25 import android.view.animation.AlphaAnimation;
     26 
     27 import com.android.internal.R;
     28 
     29 
     30 /**
     31  * The {@code ZoomControls} class displays a simple set of controls used for zooming and
     32  * provides callbacks to register for events. */
     33 @Widget
     34 public class ZoomControls extends LinearLayout {
     35 
     36     private final ZoomButton mZoomIn;
     37     private final ZoomButton mZoomOut;
     38 
     39     public ZoomControls(Context context) {
     40         this(context, null);
     41     }
     42 
     43     public ZoomControls(Context context, AttributeSet attrs) {
     44         super(context, attrs);
     45         setFocusable(false);
     46 
     47         LayoutInflater inflater = (LayoutInflater) context
     48                 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     49         inflater.inflate(R.layout.zoom_controls, this, // we are the parent
     50                 true);
     51 
     52         mZoomIn = (ZoomButton) findViewById(R.id.zoomIn);
     53         mZoomOut = (ZoomButton) findViewById(R.id.zoomOut);
     54     }
     55 
     56     public void setOnZoomInClickListener(OnClickListener listener) {
     57         mZoomIn.setOnClickListener(listener);
     58     }
     59 
     60     public void setOnZoomOutClickListener(OnClickListener listener) {
     61         mZoomOut.setOnClickListener(listener);
     62     }
     63 
     64     /*
     65      * Sets how fast you get zoom events when the user holds down the
     66      * zoom in/out buttons.
     67      */
     68     public void setZoomSpeed(long speed) {
     69         mZoomIn.setZoomSpeed(speed);
     70         mZoomOut.setZoomSpeed(speed);
     71     }
     72 
     73     @Override
     74     public boolean onTouchEvent(MotionEvent event) {
     75 
     76         /* Consume all touch events so they don't get dispatched to the view
     77          * beneath this view.
     78          */
     79         return true;
     80     }
     81 
     82     public void show() {
     83         fade(View.VISIBLE, 0.0f, 1.0f);
     84     }
     85 
     86     public void hide() {
     87         fade(View.GONE, 1.0f, 0.0f);
     88     }
     89 
     90     private void fade(int visibility, float startAlpha, float endAlpha) {
     91         AlphaAnimation anim = new AlphaAnimation(startAlpha, endAlpha);
     92         anim.setDuration(500);
     93         startAnimation(anim);
     94         setVisibility(visibility);
     95     }
     96 
     97     public void setIsZoomInEnabled(boolean isEnabled) {
     98         mZoomIn.setEnabled(isEnabled);
     99     }
    100 
    101     public void setIsZoomOutEnabled(boolean isEnabled) {
    102         mZoomOut.setEnabled(isEnabled);
    103     }
    104 
    105     @Override
    106     public boolean hasFocus() {
    107         return mZoomIn.hasFocus() || mZoomOut.hasFocus();
    108     }
    109 
    110     @Override
    111     public CharSequence getAccessibilityClassName() {
    112         return ZoomControls.class.getName();
    113     }
    114 }
    115