Home | History | Annotate | Download | only in view 
      1 /*
      2  * Copyright (C) 2011 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 com.example.android.apis.view;
     18 
     19 import com.example.android.apis.R;
     20 
     21 import android.app.Activity;
     22 import android.content.Context;
     23 import android.content.res.Resources;
     24 import android.os.Bundle;
     25 import android.util.AttributeSet;
     26 import android.util.Log;
     27 import android.view.LayoutInflater;
     28 import android.view.MotionEvent;
     29 import android.view.View;
     30 import android.view.ViewGroup;
     31 import android.widget.CheckBox;
     32 import android.widget.CompoundButton;
     33 import android.widget.LinearLayout;
     34 import android.widget.TextView;
     35 
     36 import java.util.ArrayList;
     37 
     38 
     39 /**
     40  * Demonstrates how to use {@link View#onHoverEvent}, {@link ViewGroup#onInterceptHoverEvent},
     41  * and {@link View#setOnHoverListener}.
     42  *
     43  * This activity displays a few buttons and text fields and entices the user
     44  * to hover over them using a mouse or touch pad.  It displays feedback reporting
     45  * the position of the pointing device and the label of the view being hovered.
     46  *
     47  * A button changes from dark green to bright yellow when hovered.
     48  * This effect is achieved by using a state-list drawable to select among different
     49  * background shapes and colors based on the hover state of the button.
     50  *
     51  * A {@link View#OnHoverEventListener} is used to listen for hover events within the
     52  * container.  The container will re
     53  *
     54  * A checkbox is used to control whether a special view, the Interceptor, will intercept
     55  * events before they are sent to its child (a button).  When the Interceptor
     56  * is intercepting events, the button will not change state as the pointer hovers
     57  * over it because the interceptor itself will grab the events.
     58  */
     59 public class Hover extends Activity {
     60     private TextView mMessageTextView;
     61     private CheckBox mInterceptCheckBox;
     62     private HoverInterceptorView mInterceptor;
     63 
     64     @Override
     65     protected void onCreate(Bundle savedInstanceState) {
     66         super.onCreate(savedInstanceState);
     67 
     68         setContentView(R.layout.hover);
     69 
     70         mMessageTextView = (TextView) findViewById(R.id.message);
     71         mInterceptCheckBox = (CheckBox) findViewById(R.id.intercept_checkbox);
     72         mInterceptor = (HoverInterceptorView) findViewById(R.id.interceptor);
     73 
     74         View container = findViewById(R.id.container);
     75         container.setOnHoverListener(new View.OnHoverListener() {
     76             @Override
     77             public boolean onHover(View v, MotionEvent event) {
     78                 switch (event.getAction()) {
     79                     case MotionEvent.ACTION_HOVER_ENTER:
     80                         mMessageTextView.setText(Hover.this.getResources().getString(
     81                                 R.string.hover_message_entered_at,
     82                                 event.getX(), event.getY()));
     83                         break;
     84                     case MotionEvent.ACTION_HOVER_MOVE:
     85                         mMessageTextView.setText(Hover.this.getResources().getString(
     86                                 R.string.hover_message_moved_at,
     87                                 event.getX(), event.getY()));
     88                         break;
     89                     case MotionEvent.ACTION_HOVER_EXIT:
     90                         mMessageTextView.setText(Hover.this.getResources().getString(
     91                                 R.string.hover_message_exited_at,
     92                                 event.getX(), event.getY()));
     93                         break;
     94                 }
     95                 return false;
     96             }
     97         });
     98 
     99         mInterceptCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    100             @Override
    101             public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    102                 mInterceptor.setInterceptHover(isChecked);
    103             }
    104         });
    105     }
    106 }
    107