1 /* 2 * Copyright (C) 2007 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 android.app.Activity; 20 import android.os.Bundle; 21 import android.view.ViewGroup; 22 import android.widget.LinearLayout; 23 import android.widget.ScrollView; 24 25 /** 26 * Demonstrates how a well behaved view with internal selection 27 * ({@link InternalSelectionView}) can cause its parent {@link android.widget.ScrollView} 28 * to scroll to keep the internally interesting rectangle on the screen. 29 * 30 * {@link InternalSelectionView} achieves this by calling {@link android.view.View#requestRectangleOnScreen} 31 * each time its internal selection changes. 32 * 33 * {@link android.widget.ScrollView}, in turn, implements {@link android.view.View#requestRectangleOnScreen} 34 * thereby acheiving the result. Note that {@link android.widget.ListView} also implements the 35 * method, so views that call {@link android.view.View#requestRectangleOnScreen} that are embedded 36 * within either {@link android.widget.ScrollView}s or {@link android.widget.ListView}s can 37 * expect to keep their internal interesting rectangle visible. 38 */ 39 public class InternalSelectionScroll extends Activity { 40 41 @Override 42 protected void onCreate(Bundle savedInstanceState) { 43 super.onCreate(savedInstanceState); 44 45 ScrollView sv = new ScrollView(this); 46 ViewGroup.LayoutParams svLp = new ScrollView.LayoutParams( 47 ViewGroup.LayoutParams.MATCH_PARENT, 48 ViewGroup.LayoutParams.WRAP_CONTENT); 49 50 LinearLayout ll = new LinearLayout(this); 51 ll.setLayoutParams(svLp); 52 sv.addView(ll); 53 54 InternalSelectionView isv = new InternalSelectionView(this, 10); 55 int screenHeight = getWindowManager().getDefaultDisplay().getHeight(); 56 LinearLayout.LayoutParams llLp = new LinearLayout.LayoutParams( 57 ViewGroup.LayoutParams.MATCH_PARENT, 58 2 * screenHeight); // 2x screen height to ensure scrolling 59 isv.setLayoutParams(llLp); 60 ll.addView(isv); 61 62 setContentView(sv); 63 } 64 } 65
