// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_DISPLAY_WIN_SCALING_UTIL_H_
#define UI_DISPLAY_WIN_SCALING_UTIL_H_
#include <stdint.h>
#include "ui/display/display_export.h"
#include "ui/display/display_layout.h"
#include "ui/display/win/display_info.h"
namespace gfx {
class Rect;
}
namespace display {
namespace win {
// Whether or not |a| shares an edge with |b|.
DISPLAY_EXPORT bool DisplayInfosTouch(const internal::DisplayInfo& a,
const internal::DisplayInfo& b);
// Returns a DisplayPlacement for |current| relative to |parent|.
// Note that DisplayPlacement's are always in DIPs, so this also performs the
// required scaling.
//
// Examples (The offset is indicated by the arrow.):
// Scaled and Unscaled Coordinates
// +--------------+ + Since both DisplayInfos are of the same scale
// | | | factor, relative positions remain the same.
// | Parent | V
// | 1x +----------+
// | | |
// +--------------+ Current |
// | 1x |
// +----------+
//
// Unscaled Coordinates
// +--------------+ The 2x DisplayInfo is offset to maintain a
// | | similar neighboring relationship with the 1x
// | Parent | parent. Current's position is based off of the
// | 1x +----------+ percentage position along its parent. This
// | | | percentage position is preserved in the scaled
// +--------------+ Current | coordinates.
// | 2x |
// +----------+
// Scaled Coordinates
// +--------------+ +
// | | |
// | Parent | V
// | 1x +-----+
// | + C 2x|
// +--------------+-----+
//
//
// Unscaled Coordinates
// +--------------+ The parent DisplayInfo has a 2x scale factor.
// | | The offset is adjusted to maintain the
// | | relative positioning of the 1x DisplayInfo in
// | Parent +----------+ the scaled coordinate space. Current's
// | 2x | | position is based off of the percentage
// | | Current | position along its parent. This percentage
// | | 1x | position is preserved in the scaled
// +--------------+ | coordinates.
// | |
// +----------+
// Scaled Coordinates
// +-------+ +
// | | V
// | Parent+----------+
// | 2x | |
// +-------+ Current |
// | 1x |
// | |
// | |
// +----------+
//
// Unscaled Coordinates
// +----------+ In this case, parent lies between the top and
// | | bottom of parent. The roles are reversed when
// +-------+ | this occurs, and current is placed to maintain
// | | Current | parent's relative position along current.
// | Parent| 1x |
// | 2x | |
// +-------+ |
// +----------+
// Scaled Coordinates
// ^ +----------+
// | | |
// + +----+ |
// |Prnt| Current |
// | 2x | 1x |
// +----+ |
// | |
// +----------+
//
// Scaled and Unscaled Coordinates
// +--------+ If the two DisplayInfos are bottom aligned or
// | | right aligned, the DisplayPlacement will
// | +--------+ have an offset of 0 relative to the
// | | | bottom-right of the DisplayInfo.
// | | |
// +--------+--------+
DISPLAY_EXPORT DisplayPlacement
CalculateDisplayPlacement(const internal::DisplayInfo& parent,
const internal::DisplayInfo& current);
// Returns the squared distance between two rects.
// The distance between two rects is the length of the shortest segment that can
// be drawn between two rectangles. This segment generally connects two opposing
// corners between rectangles like this...
//
// +----------+
// | |
// +----------+
// \ <--- Shortest Segment
// \
// +---+
// | |
// | |
// +---+
//
// For rectangles that share coordinates within the same axis, that generally
// means the segment is parallel to the axis and perpendicular to the edges.
//
// One of many shortest segments
// +----------+ / \ +--------+
// | | | \ | |
// | | V +---+ \ +--------+
// | |-----| | \-->|
// +----------+ | | +----+
// | | | |
// +---+ +----+
//
// For rectangles that intersect each other, the distance is the negative value
// of the overlapping area, so callers can distinguish different amounts of
// overlap.
//
// The squared distance is used to avoid taking the square root as the common
// usage is to compare distances greater than 1 unit.
DISPLAY_EXPORT int64_t SquaredDistanceBetweenRects(const gfx::Rect& ref,
const gfx::Rect& rect);
} // namespace win
} // namespace display
#endif // UI_DISPLAY_WIN_SCALING_UTIL_H_
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