// Copyright 2015 The Chromium Authors
// 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.base.MathUtils;
import org.chromium.chrome.browser.compositor.layouts.Layout;
import org.chromium.ui.base.LocalizationUtils;
/**
* An interface that defines how to stack views and how they should look visually. This lets certain
* components customize how the {@link StripLayoutHelper} functions and how other {@link Layout}s
* visually order tabs.
*/
public abstract class StripStacker {
/**
* This gives the implementing class a chance to determine how the tabs should be ordered
* visually. The positioning logic is the same regardless, this just has to do with visual
* stacking.
*
* @param selectedIndex The selected index of the tabs.
* @param indexOrderedTabs A list of tabs ordered by index.
* @param outVisualOrderedTabs The new list of tabs, ordered from back (low z-index) to front
* (high z-index) visually.
*/
public void createVisualOrdering(
int selectedIndex,
StripLayoutTab[] indexOrderedTabs,
StripLayoutTab[] outVisualOrderedTabs) {
// TODO(crbug.com/40268645): Stacking order can be ignored for TSR.
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];
}
}
/**
* Computes and sets the draw X, draw Y, visibility and content offset for each view.
*
* @param indexOrderedViews A list of tabs ordered by index.
* @param tabClosing Whether a tab is being closed.
* @param groupTitleSlidingAnimRunning Whether a group title is sliding for reorder.
* @param cachedTabWidth Whether The ideal tab width.
*/
public abstract void setViewOffsets(
StripLayoutView[] indexOrderedViews,
boolean tabClosing,
boolean groupTitleSlidingAnimRunning,
float cachedTabWidth);
/**
* Computes the X offset for the new tab button.
*
* @param indexOrderedTabs A list of tabs ordered by index.
* @param tabOverlapWidth The amount tabs overlap.
* @param stripLeftMargin The left margin of the tab strip.
* @param stripRightMargin The right margin of the tab strip.
* @param stripWidth The width of the tab strip.
* @param buttonWidth The width of the new tab button.
* @return The x offset for the new tab button.
*/
public float computeNewTabButtonOffset(
StripLayoutTab[] indexOrderedTabs,
float tabOverlapWidth,
float stripLeftMargin,
float stripRightMargin,
float stripWidth,
float buttonWidth) {
return LocalizationUtils.isLayoutRtl()
? computeNewTabButtonOffsetRtl(
indexOrderedTabs,
stripLeftMargin,
stripRightMargin,
stripWidth,
buttonWidth)
: computeNewTabButtonOffsetLtr(
indexOrderedTabs,
tabOverlapWidth,
stripLeftMargin,
stripRightMargin,
stripWidth);
}
private float computeNewTabButtonOffsetLtr(
StripLayoutTab[] indexOrderedTabs,
float tabOverlapWidth,
float stripLeftMargin,
float stripRightMargin,
float stripWidth) {
float rightEdge = stripLeftMargin;
for (StripLayoutTab tab : indexOrderedTabs) {
if (tab.isDying() || tab.isDraggedOffStrip()) continue;
float layoutWidth = (tab.getWidth() - tabOverlapWidth) * tab.getWidthWeight();
rightEdge = Math.max(tab.getDrawX() + layoutWidth, rightEdge);
}
// The draw X position for the new tab button is the rightEdge of the tab strip.
return Math.min(rightEdge + tabOverlapWidth, stripWidth - stripRightMargin);
}
private float computeNewTabButtonOffsetRtl(
StripLayoutTab[] indexOrderedTabs,
float stripLeftMargin,
float stripRightMargin,
float stripWidth,
float newTabButtonWidth) {
float leftEdge = stripWidth - stripRightMargin;
for (StripLayoutTab tab : indexOrderedTabs) {
if (tab.isDying() || tab.isDraggedOffStrip()) continue;
leftEdge = Math.min(tab.getDrawX(), leftEdge);
}
// The draw X position for the new tab button is the left edge of the tab strip minus
// the new tab button width.
return Math.max(leftEdge, stripLeftMargin) - newTabButtonWidth;
}
/**
* Performs an occlusion pass, setting the visibility on tabs. This is relegated to this
* interface because the implementing class knows the proper visual order to optimize this pass.
*
* @param indexOrderedViews A list of views ordered by index.
* @param xOffset The xOffset for the start of the strip.
* @param visibleWidth The width of the visible space on the tab strip.
*/
public abstract void performOcclusionPass(
StripLayoutView[] indexOrderedViews, float xOffset, float visibleWidth);
}