Index: ash/common/system/tray/three_view_layout.h |
diff --git a/ash/common/system/tray/three_view_layout.h b/ash/common/system/tray/three_view_layout.h |
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+// Copyright 2016 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. |
+ |
+#ifndef ASH_COMMON_SYSTEM_TRAY_THREE_VIEW_LAYOUT_H_ |
+#define ASH_COMMON_SYSTEM_TRAY_THREE_VIEW_LAYOUT_H_ |
+ |
+#include <memory> |
+ |
+#include "ash/ash_export.h" |
+#include "base/macros.h" |
+#include "ui/gfx/geometry/insets.h" |
+#include "ui/gfx/geometry/size.h" |
+#include "ui/views/layout/layout_manager.h" |
+ |
+namespace views { |
+class Border; |
+class BoxLayout; |
+class View; |
+} // namespace views |
+ |
+namespace ash { |
+class SizeRangeLayout; |
+ |
+// A layout manager that has 3 child containers (START, CENTER, END) which can |
+// be arranged vertically or horizontally. The child containers can have |
+// minimum and/or maximum preferred size defined as well as a flex weight that |
+// is used to distribute excess space across the main axis, i.e. flexible width |
+// for the horizontal orientation. By default all the containers have a flex |
+// weight of 0, meaning no flexibility, and no minimum or maximum size. |
+// |
+// Views are laid out within each container as per the LayoutManager that has |
+// been installed on that container. By default a BoxLayout manager is installed |
+// on each container with the same orientation as |this| has been created with. |
+// The default BoxLayout will use a center alignment for both the main axis and |
+// cross axis alignment. |
+class ASH_EXPORT ThreeViewLayout : public views::LayoutManager { |
+ public: |
+ enum class Orientation { |
+ HORIZONTAL, |
+ VERTICAL, |
+ }; |
+ |
+ // The different containers that child Views can be added to. |
+ enum class Container { START, CENTER, END }; |
+ |
+ // Constructs a layout with horizontal orientation and 0 padding between |
+ // containers. |
+ ThreeViewLayout(); |
+ |
+ // Constructs a layout with Horizontal orientation and the specified padding |
+ // between containers. |
+ // |
+ // TODO(bruthig): The |padding_between_containers| can only be set on |
+ // BoxLayouts during construction. Investigate whether this can be a mutable |
+ // property of BoxLayouts and if so consider dropping it as a constructor |
+ // parameter here. |
+ explicit ThreeViewLayout(int padding_between_containers); |
+ |
+ // Constructs a layout with the specified orientation and 0 padding between |
+ // containers. |
+ explicit ThreeViewLayout(Orientation orientation); |
+ |
+ // Constructs a layout with the specified orientation and padding between |
+ // containers. |
+ ThreeViewLayout(Orientation orientation, int padding_between_containers); |
+ |
+ ~ThreeViewLayout() override; |
+ |
+ // Set the minimum cross axis size for the layout, i.e. the minimum height for |
+ // a horizontal orientation. |
+ void SetMinCrossAxisSize(int min_size); |
+ |
+ // Set the minimum size for the given |container|. |
+ void SetMinSize(Container container, const gfx::Size& size); |
+ |
+ // Set the maximum size for the given |container|. |
+ void SetMaxSize(Container container, const gfx::Size& size); |
+ |
+ // Adds the child |view| to the specified |container|. |
+ void AddView(Container container, views::View* view); |
+ |
+ // Removes all current children from the specified |container| and adds the |
+ // child |view| to it. |
+ void SetView(Container container, views::View* view); |
+ |
+ // During layout the |insets| are applied to the host views entire space |
+ // before allocating the remaining space to the container views. |
+ void SetInsets(const gfx::Insets& insets); |
+ |
+ // Sets the border for the given |container|. |
+ void SetBorder(Container container, std::unique_ptr<views::Border> border); |
+ |
+ // Sets wither the |container| is visible. During a layout the space will be |
+ // allocated to the visible containers only. i.e. non-visible containers will |
+ // not be allocated any space. |
+ void SetContainerVisible(Container container, bool visible); |
+ |
+ // Sets the flex weight for the given |container|. Using the preferred size as |
+ // the basis, free space along the main axis is distributed to views in the |
+ // ratio of their flex weights. Similarly, if the views will overflow the |
+ // parent, space is subtracted in these ratios. |
+ // |
+ // A flex of 0 means this view is not resized. Flex values must not be |
+ // negative. |
+ // |
+ // Note that non-zero flex values will take precedence over size constraints. |
+ // i.e. even if |container| has a max size set the space allocated during |
+ // layout may be larger if |flex| > 0 and similar for min size constraints. |
+ void SetFlexForContainer(Container container, int flex); |
+ |
+ // Sets the |layout_manager| used by the given |container|. |
+ void SetLayoutManager(Container container, |
+ std::unique_ptr<LayoutManager> layout_manager); |
+ |
+ // LayoutManager: |
+ void Installed(views::View* host) override; |
+ void Layout(views::View* host) override; |
+ gfx::Size GetPreferredSize(const views::View* host) const override; |
+ int GetPreferredHeightForWidth(const views::View* host, |
+ int width) const override; |
+ void ViewAdded(views::View* host, views::View* view) override; |
+ void ViewRemoved(views::View* host, views::View* view) override; |
+ |
+ private: |
+ friend class ThreeViewLayoutTest; |
+ |
+ // Creates a default LayoutManager for the given |orientation|. |
+ std::unique_ptr<views::LayoutManager> CreateDefaultLayoutManager( |
+ Orientation orientation) const; |
+ |
+ // Returns the View for the given |container|. |
+ views::View* GetContainer(Container container) const; |
+ |
+ // Returns the layout manager for the given |container|. |
+ SizeRangeLayout* GetLayoutManager(Container container) const; |
+ |
+ // The layout manager that lays out the different Container Views. |
+ std::unique_ptr<views::BoxLayout> box_layout_; |
+ |
+ // The host View that this layout manager has been installed on. |
+ views::View* host_ = nullptr; |
+ |
+ views::View* start_container_ = nullptr; |
+ SizeRangeLayout* start_container_layout_manager_ = nullptr; |
+ |
+ views::View* center_container_ = nullptr; |
+ SizeRangeLayout* center_container_layout_manager_ = nullptr; |
+ |
+ views::View* end_container_ = nullptr; |
+ SizeRangeLayout* end_container_layout_manager_ = nullptr; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(ThreeViewLayout); |
+}; |
+ |
+} // namespace ash |
+ |
+#endif // ASH_COMMON_SYSTEM_TRAY_THREE_VIEW_LAYOUT_H_ |