Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/ntp/IconMostVisitedLayout.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.ntp;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.FrameLayout;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.chrome.browser.util.MathUtils;
+
+/**
+ * A layout that arranges most visited items in a grid.
+ *
+ * Intended for use with the new icon-based most visited items.
+ */
+public class IconMostVisitedLayout extends FrameLayout {
+
+    private static final int MAX_COLUMNS = 4;
+
+    private int mVerticalSpacing;
+    private int mMinHorizontalSpacing;
+    private int mMaxHorizontalSpacing;
+    private int mMaxWidth;
+
+    /**
+     * @param context The view context in which this item will be shown.
+     * @param attrs The attributes of the XML tag that is inflating the view.
+     */
+    public IconMostVisitedLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+
+        Resources res = getResources();
+        mVerticalSpacing = res.getDimensionPixelOffset(R.dimen.icon_most_visited_vertical_spacing);
+        mMinHorizontalSpacing = res.getDimensionPixelOffset(
+                R.dimen.icon_most_visited_min_horizontal_spacing);
+        mMaxHorizontalSpacing = res.getDimensionPixelOffset(
+                R.dimen.icon_most_visited_max_horizontal_spacing);
+        mMaxWidth = res.getDimensionPixelOffset(R.dimen.icon_most_visited_layout_max_width);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        int totalWidth = resolveSize(mMaxWidth, widthMeasureSpec);
+        int childCount = getChildCount();
+        if (childCount == 0) {
+            setMeasuredDimension(totalWidth, resolveSize(0, heightMeasureSpec));
+            return;
+        }
+
+        // Measure the children.
+        for (int i = 0; i < childCount; i++) {
+            measureChild(getChildAt(i), MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
+        }
+
+        // Determine the number of columns that will fit.
+        int gridWidth = totalWidth - ApiCompatibilityUtils.getPaddingStart(this)
+                - ApiCompatibilityUtils.getPaddingEnd(this);
+        int childHeight = getChildAt(0).getMeasuredHeight();
+        int childWidth = getChildAt(0).getMeasuredWidth();
+        int numColumns = MathUtils.clamp(
+                (gridWidth + mMinHorizontalSpacing) / (childWidth + mMinHorizontalSpacing),
+                1, MAX_COLUMNS);
+
+        // Ensure column spacing isn't greater than mMaxHorizontalSpacing.
+        int gridWidthMinusColumns = Math.max(0, gridWidth - numColumns * childWidth);
+        int gridSidePadding = gridWidthMinusColumns - mMaxHorizontalSpacing * (numColumns - 1);
+
+        int gridStart = 0;
+        float horizontalSpacing;
+        if (gridSidePadding > 0) {
+            horizontalSpacing = mMaxHorizontalSpacing;
+            gridStart = gridSidePadding / 2;
+        } else {
+            horizontalSpacing = (float) gridWidthMinusColumns / Math.max(1, numColumns - 1);
+        }
+
+        // Arrange the children in a grid.
+        int paddingTop = getPaddingTop();
+        boolean isRtl = ApiCompatibilityUtils.isLayoutRtl(this);
+        for (int i = 0; i < childCount; i++) {
+            View child = getChildAt(i);
+            int row = i / numColumns;
+            int column = i % numColumns;
+            int childTop = row * (childHeight + mVerticalSpacing);
+            int childStart = gridStart + Math.round(column * (childWidth + horizontalSpacing));
+            MarginLayoutParams layoutParams = (MarginLayoutParams) child.getLayoutParams();
+            layoutParams.setMargins(isRtl ? 0 : childStart, childTop, isRtl ? childStart : 0, 0);
+            child.setLayoutParams(layoutParams);
+        }
+
+        int numRows = (childCount + numColumns - 1) / numColumns;
+        int totalHeight = paddingTop + getPaddingBottom() + numRows * childHeight
+                + (numRows - 1) * mVerticalSpacing;
+
+        setMeasuredDimension(totalWidth, resolveSize(totalHeight, heightMeasureSpec));
+    }
+}