Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/widget/FlowLayout.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.widget;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.base.ApiCompatibilityUtils;
+
+/**
+ * ViewGroup that places child views in lines from start to end, wraps items to
+ * next line if content too long to hold in one line.
+ */
+public class FlowLayout extends ViewGroup {
+    private static final int SPACING_DEFAULT_DP = 3;
+
+    private int mHorizontalSpacing;
+    private int mVerticalSpacing;
+
+    public FlowLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        int spacingDefaultPx = Math.round(
+                getResources().getDisplayMetrics().density * SPACING_DEFAULT_DP);
+        mHorizontalSpacing = spacingDefaultPx;
+        mVerticalSpacing = spacingDefaultPx;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        int availableWidth = MeasureSpec.getSize(widthMeasureSpec)
+                - ApiCompatibilityUtils.getPaddingEnd(this);
+        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
+
+        boolean growHeight = widthMode != MeasureSpec.UNSPECIFIED;
+
+        int width = 0;
+        int height = getPaddingTop();
+
+        int currentWidth = ApiCompatibilityUtils.getPaddingStart(this);
+        int currentHeight = 0;
+
+        boolean newLine = false;
+        int spacing = 0;
+
+        final int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            View child = getChildAt(i);
+            measureChild(child, widthMeasureSpec, heightMeasureSpec);
+
+            LayoutParams lp = (LayoutParams) child.getLayoutParams();
+            spacing = mHorizontalSpacing;
+
+            if (growHeight && currentWidth + child.getMeasuredWidth() > availableWidth) {
+                height += currentHeight + mVerticalSpacing;
+                currentHeight = 0;
+                width = Math.max(width, currentWidth - spacing);
+                currentWidth = ApiCompatibilityUtils.getPaddingStart(this);
+                newLine = true;
+            } else {
+                newLine = false;
+            }
+
+            lp.start = currentWidth;
+            lp.top = height;
+
+            currentWidth += child.getMeasuredWidth() + spacing;
+            currentHeight = Math.max(currentHeight, child.getMeasuredHeight());
+
+        }
+
+        if (!newLine) {
+            height += currentHeight;
+            width = Math.max(width, currentWidth - spacing);
+        }
+
+        width += ApiCompatibilityUtils.getPaddingEnd(this);
+        height += getPaddingBottom();
+
+        setMeasuredDimension(resolveSize(width, widthMeasureSpec),
+                resolveSize(height, heightMeasureSpec));
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        // Entire width of layout group
+        int width = r - l;
+        boolean isRtl = ApiCompatibilityUtils.isLayoutRtl(this);
+        for (int i = 0; i < getChildCount(); i++) {
+            View child = getChildAt(i);
+            LayoutParams lp = (LayoutParams) child.getLayoutParams();
+            int left = isRtl ? width - lp.start - child.getMeasuredWidth() : lp.start;
+            child.layout(left, lp.top, left + child.getMeasuredWidth(),
+                    lp.top + child.getMeasuredHeight());
+        }
+    }
+
+    @Override
+    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
+        return p instanceof LayoutParams;
+    }
+
+    @Override
+    protected LayoutParams generateDefaultLayoutParams() {
+        return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
+    }
+
+    @Override
+    public LayoutParams generateLayoutParams(AttributeSet attrs) {
+        return new LayoutParams(getContext(), attrs);
+    }
+
+    @Override
+    protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
+        return new LayoutParams(p.width, p.height);
+    }
+
+    /**
+     * LayoutParams for FlowLayout.
+     */
+    public static class LayoutParams extends ViewGroup.LayoutParams {
+        // distance from start of view group to start of the view.
+        public int start;
+        // vertical coordinate of the view
+        public int top;
+
+        public LayoutParams(Context context, AttributeSet attrs) {
+            super(context, attrs);
+        }
+
+        public LayoutParams(int w, int h) {
+            super(w, h);
+        }
+    }
+}