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      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 
     34     public CalculatorPadLayout(Context context) {
     35         this(context, null);
     36     }
     37 
     38     public CalculatorPadLayout(Context context, AttributeSet attrs) {
     39         this(context, attrs, 0);
     40     }
     41 
     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
     54     public boolean shouldDelayChildPressedState() {
     55         return false;
     56     }
     57 
     58     @Override
     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
    102     public LayoutParams generateLayoutParams(AttributeSet attrs) {
    103         return new MarginLayoutParams(getContext(), attrs);
    104     }
    105 
    106     @Override
    107     protected LayoutParams generateDefaultLayoutParams() {
    108         return new MarginLayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    109     }
    110 
    111     @Override
    112     protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
    113         return new MarginLayoutParams(p);
    114     }
    115 
    116     @Override
    117     protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    118         return p instanceof MarginLayoutParams;
    119     }
    120 }
    121