Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/overlays/strip/StaticStripStacker.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.compositor.overlays.strip;
+
+import org.chromium.chrome.browser.util.MathUtils;
+
+/**
+ * A stacker that tells the {@link StripHelper} how to layer the tabs for the
+ * {@link StaticLayout}.  This will basically be focused tab in front with tabs cascading
+ * back to each side.
+ */
+public class StaticStripStacker implements StripStacker {
+    @Override
+    public boolean canShowCloseButton() {
+        return true;
+    }
+
+    @Override
+    public boolean canSlideTitleText() {
+        return true;
+    }
+
+    @Override
+    public void createVisualOrdering(int selectedIndex, StripLayoutTab[] indexOrderedTabs,
+            StripLayoutTab[] outVisualOrderedTabs) {
+        assert indexOrderedTabs.length == outVisualOrderedTabs.length;
+
+        selectedIndex = MathUtils.clamp(selectedIndex, 0, indexOrderedTabs.length);
+
+        int outIndex = 0;
+        for (int i = 0; i < selectedIndex; i++) {
+            outVisualOrderedTabs[outIndex++] = indexOrderedTabs[i];
+        }
+
+        for (int i = indexOrderedTabs.length - 1; i >= selectedIndex; --i) {
+            outVisualOrderedTabs[outIndex++] = indexOrderedTabs[i];
+        }
+    }
+
+    @Override
+    public void performOcclusionPass(int selectedIndex, StripLayoutTab[] indexOrderedTabs) {
+        for (int i = 1; i < indexOrderedTabs.length; i++) {
+            StripLayoutTab prevTab = indexOrderedTabs[i - 1];
+            StripLayoutTab currTab = indexOrderedTabs[i];
+
+            if ((int) prevTab.getDrawY() == (int) currTab.getDrawY()
+                    && (int) prevTab.getDrawX() == (int) currTab.getDrawX()) {
+                if (i <= selectedIndex) {
+                    prevTab.setVisible(false);
+                } else if (i > selectedIndex) {
+                    currTab.setVisible(false);
+                }
+            } else if ((int) prevTab.getDrawX() != (int) currTab.getDrawX()) {
+                if (i <= selectedIndex) {
+                    prevTab.setVisible(true);
+                } else if (i > selectedIndex) {
+                    currTab.setVisible(true);
+                }
+            }
+
+            if (i == selectedIndex) currTab.setVisible(true);
+        }
+    }
+}