1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_UI_APP_LIST_APP_LIST_POSITIONER_H_ 6 #define CHROME_BROWSER_UI_APP_LIST_APP_LIST_POSITIONER_H_ 7 8 #include "ui/gfx/display.h" 9 #include "ui/gfx/size.h" 10 11 namespace gfx { 12 class Point; 13 class Rect; 14 } 15 16 // Helps anchor the App List, onto the shelf (taskbar, dock or similar) or to 17 // the corner of a display. This class does not impose any particular policy for 18 // when and how to anchor the window. The platform-specific code that uses this 19 // class is free to decide, for example, when the window should be anchored to 20 // the cursor versus the corner of the shelf. This class just performs the 21 // calculations necessary to position the App List correctly. 22 class AppListPositioner { 23 public: 24 // Represents one of the four edges of the screen. 25 enum ScreenEdge { 26 SCREEN_EDGE_UNKNOWN, 27 SCREEN_EDGE_LEFT, 28 SCREEN_EDGE_RIGHT, 29 SCREEN_EDGE_TOP, 30 SCREEN_EDGE_BOTTOM 31 }; 32 33 // Represents one of the four corners of the screen. 34 enum ScreenCorner { 35 SCREEN_CORNER_TOP_LEFT, 36 SCREEN_CORNER_TOP_RIGHT, 37 SCREEN_CORNER_BOTTOM_LEFT, 38 SCREEN_CORNER_BOTTOM_RIGHT 39 }; 40 41 // The |display| pointer is borrowed, and must outlive this object's lifetime. 42 // |window_size| is the size of the App List. 43 // |min_distance_from_edge| is the minimum distance, in pixels, to position 44 // the app list from the shelf or edge of screen. 45 AppListPositioner(const gfx::Display& display, 46 const gfx::Size& window_size, 47 int min_distance_from_edge); 48 49 // Subtracts a rectangle from the display's work area. This can be used to 50 // ensure that the app list does not overlap the shelf, even in situations 51 // where the shelf is considered part of the work area. 52 void WorkAreaSubtract(const gfx::Rect& rect); 53 54 // Shrinks the display's work area by the given amount on each side. 55 void WorkAreaInset(int left, int top, int right, int bottom); 56 57 // Finds the position for a window to anchor it to a corner of the screen. 58 // |corner| specifies which corner to anchor the window to. Returns the 59 // intended coordinates for the center of the window. This should only be used 60 // when there is no shelf on the display, because if there is, the returned 61 // anchor point will potentially position the window under it. 62 gfx::Point GetAnchorPointForScreenCorner(ScreenCorner corner) const; 63 64 // Finds the position for a window to anchor it to the center of the screen. 65 // Returns the intended coordinates for the center of the window. 66 gfx::Point GetAnchorPointForScreenCenter() const; 67 68 // Finds the position for a window to anchor it to the corner of the shelf. 69 // The window will be aligned to the left of the work area for horizontal 70 // shelves, or to the top for vertical shelves. |shelf_edge| specifies the 71 // location of the shelf. |shelf_edge| must not be SCREEN_EDGE_UNKNOWN. 72 // Returns the intended coordinates for the center of the window. 73 gfx::Point GetAnchorPointForShelfCorner(ScreenEdge shelf_edge) const; 74 75 // Finds the position for a window to anchor it to the center of the shelf. 76 // |shelf_edge| specifies the location of the shelf. It must not be 77 // SCREEN_EDGE_UNKNOWN. Returns the intended coordinates for the center of the 78 // window. 79 gfx::Point GetAnchorPointForShelfCenter(ScreenEdge shelf_edge) const; 80 81 // Finds the position for a window to anchor it to the shelf at a point 82 // closest to the user's mouse cursor. |shelf_edge| specifies the location of 83 // the shelf; |cursor| specifies the location of the user's mouse cursor. 84 // |shelf_edge| must not be SCREEN_EDGE_UNKNOWN. Returns the intended 85 // coordinates for the center of the window. 86 gfx::Point GetAnchorPointForShelfCursor(ScreenEdge shelf_edge, 87 const gfx::Point& cursor) const; 88 89 // Determines which edge of the screen the shelf is attached to. Returns 90 // SCREEN_EDGE_UNKNOWN if the shelf is unavailable, hidden, or not on the 91 // current screen. 92 ScreenEdge GetShelfEdge(const gfx::Rect& shelf_rect) const; 93 94 // Gets the lateral distance of the mouse cursor from the edge of the shelf. 95 // For horizontal shelves, this is the vertical distance; for vertical 96 // shelves, this is the horizontal distance. If the cursor is inside the 97 // shelf, returns 0. 98 int GetCursorDistanceFromShelf(ScreenEdge shelf_edge, 99 const gfx::Point& cursor) const; 100 101 private: 102 // Ensures that an anchor point will result in a window that is fully within 103 // the work area. Returns the updated anchor point. 104 gfx::Point ClampAnchorPoint(gfx::Point anchor) const; 105 106 gfx::Display display_; 107 108 // Size of the App List. 109 gfx::Size window_size_; 110 111 // The minimum distance, in pixels, to position the app list from the shelf 112 // or edge of screen. 113 int min_distance_from_edge_; 114 }; 115 116 #endif // CHROME_BROWSER_UI_APP_LIST_APP_LIST_POSITIONER_H_ 117
