1 /*
2  * Copyright (C) 2014 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.android.calculator2;
18 
19 import android.content.Context;
20 import android.content.res.TypedArray;
21 import android.util.AttributeSet;
22 import android.view.View;
23 import android.view.ViewGroup;
24 
25 /**
26  * A layout that places children in an evenly distributed grid based on the specified
27  *  {@link android.R.attr#columnCount} and {@link android.R.attr#rowCount} attributes.
28  */
29 public class CalculatorPadLayout extends ViewGroup {
30 
31     private int mRowCount;
32     private int mColumnCount;
33 
CalculatorPadLayout(Context context)34     public CalculatorPadLayout(Context context) {
35         this(context, null);
36     }
37 
CalculatorPadLayout(Context context, AttributeSet attrs)38     public CalculatorPadLayout(Context context, AttributeSet attrs) {
39         this(context, attrs, 0);
40     }
41 
CalculatorPadLayout(Context context, AttributeSet attrs, int defStyle)42     public CalculatorPadLayout(Context context, AttributeSet attrs, int defStyle) {
43         super(context, attrs, defStyle);
44 
45         final TypedArray a = context.obtainStyledAttributes(attrs,
46                 new int[] { android.R.attr.rowCount, android.R.attr.columnCount }, defStyle, 0);
47         mRowCount = a.getInt(0, 1);
48         mColumnCount = a.getInt(1, 1);
49 
50         a.recycle();
51     }
52 
53     @Override
shouldDelayChildPressedState()54     public boolean shouldDelayChildPressedState() {
55         return false;
56     }
57 
58     @Override
onLayout(boolean changed, int left, int top, int right, int bottom)59     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
60         final int paddingLeft = getPaddingLeft();
61         final int paddingRight = getPaddingRight();
62         final int paddingTop = getPaddingTop();
63         final int paddingBottom = getPaddingBottom();
64 
65         final boolean isRTL = getLayoutDirection() == LAYOUT_DIRECTION_RTL;
66         final int columnWidth =
67                 Math.round((float) (right - left - paddingLeft - paddingRight)) / mColumnCount;
68         final int rowHeight =
69                 Math.round((float) (bottom - top - paddingTop - paddingBottom)) / mRowCount;
70 
71         int rowIndex = 0, columnIndex = 0;
72         for (int childIndex = 0; childIndex < getChildCount(); ++childIndex) {
73             final View childView = getChildAt(childIndex);
74             if (childView.getVisibility() == View.GONE) {
75                 continue;
76             }
77 
78             final MarginLayoutParams lp = (MarginLayoutParams) childView.getLayoutParams();
79 
80             final int childTop = paddingTop + lp.topMargin + rowIndex * rowHeight;
81             final int childBottom = childTop - lp.topMargin - lp.bottomMargin + rowHeight;
82             final int childLeft = paddingLeft + lp.leftMargin +
83                     (isRTL ? (mColumnCount - 1) - columnIndex : columnIndex) * columnWidth;
84             final int childRight = childLeft - lp.leftMargin - lp.rightMargin + columnWidth;
85 
86             final int childWidth = childRight - childLeft;
87             final int childHeight = childBottom - childTop;
88             if (childWidth != childView.getMeasuredWidth() ||
89                     childHeight != childView.getMeasuredHeight()) {
90                 childView.measure(
91                         MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY),
92                         MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.EXACTLY));
93             }
94             childView.layout(childLeft, childTop, childRight, childBottom);
95 
96             rowIndex = (rowIndex + (columnIndex + 1) / mColumnCount) % mRowCount;
97             columnIndex = (columnIndex + 1) % mColumnCount;
98         }
99     }
100 
101     @Override
generateLayoutParams(AttributeSet attrs)102     public LayoutParams generateLayoutParams(AttributeSet attrs) {
103         return new MarginLayoutParams(getContext(), attrs);
104     }
105 
106     @Override
generateDefaultLayoutParams()107     protected LayoutParams generateDefaultLayoutParams() {
108         return new MarginLayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
109     }
110 
111     @Override
generateLayoutParams(ViewGroup.LayoutParams p)112     protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
113         return new MarginLayoutParams(p);
114     }
115 
116     @Override
checkLayoutParams(ViewGroup.LayoutParams p)117     protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
118         return p instanceof MarginLayoutParams;
119     }
120 }
121