chromeos: Move files in //ash/common to //ash

ash/common/wm/workspace/magnetism_matcher.h

-// Copyright (c) 2012 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_WM_WORKSPACE_MAGNETISM_MATCHER_H_
-#define ASH_COMMON_WM_WORKSPACE_MAGNETISM_MATCHER_H_
-
-#include <stdint.h>
-
-#include <memory>
-#include <utility>
-#include <vector>
-
-#include "ash/ash_export.h"
-#include "base/compiler_specific.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "ui/gfx/geometry/rect.h"
-
-namespace ash {
-
-enum MagnetismEdge {
-  MAGNETISM_EDGE_TOP = 1 << 0,
-  MAGNETISM_EDGE_LEFT = 1 << 1,
-  MAGNETISM_EDGE_BOTTOM = 1 << 2,
-  MAGNETISM_EDGE_RIGHT = 1 << 3,
-};
-
-const uint32_t kAllMagnetismEdges = MAGNETISM_EDGE_TOP | MAGNETISM_EDGE_LEFT |
-                                    MAGNETISM_EDGE_BOTTOM |
-                                    MAGNETISM_EDGE_RIGHT;
-
-// MagnetismEdgeMatcher is used for matching a particular edge of a window. You
-// shouldn't need to use this directly, instead use MagnetismMatcher which takes
-// care of all edges.
-// MagnetismEdgeMatcher maintains a range of the visible portions of the
-// edge. As ShouldAttach() is invoked the visible range is updated.
-class MagnetismEdgeMatcher {
- public:
-  MagnetismEdgeMatcher(const gfx::Rect& bounds, MagnetismEdge edge);
-  ~MagnetismEdgeMatcher();
-
-  MagnetismEdge edge() const { return edge_; }
-  const gfx::Rect& bounds() const { return bounds_; }
-
-  // Returns true if the edge is completely obscured. If true ShouldAttach()
-  // will return false.
-  bool is_edge_obscured() const { return ranges_.empty(); }
-
-  // Returns true if should attach to the specified bounds.
-  bool ShouldAttach(const gfx::Rect& bounds);
-
- private:
-  typedef std::pair<int, int> Range;
-  typedef std::vector<Range> Ranges;
-
-  // Removes |range| from |ranges_|.
-  void UpdateRanges(const Range& range);
-
-  static int GetPrimaryCoordinate(const gfx::Rect& bounds, MagnetismEdge edge) {
-    switch (edge) {
-      case MAGNETISM_EDGE_TOP:
-        return bounds.y();
-      case MAGNETISM_EDGE_LEFT:
-        return bounds.x();
-      case MAGNETISM_EDGE_BOTTOM:
-        return bounds.bottom();
-      case MAGNETISM_EDGE_RIGHT:
-        return bounds.right();
-    }
-    NOTREACHED();
-    return 0;
-  }
-
-  static MagnetismEdge FlipEdge(MagnetismEdge edge) {
-    switch (edge) {
-      case MAGNETISM_EDGE_TOP:
-        return MAGNETISM_EDGE_BOTTOM;
-      case MAGNETISM_EDGE_BOTTOM:
-        return MAGNETISM_EDGE_TOP;
-      case MAGNETISM_EDGE_LEFT:
-        return MAGNETISM_EDGE_RIGHT;
-      case MAGNETISM_EDGE_RIGHT:
-        return MAGNETISM_EDGE_LEFT;
-    }
-    NOTREACHED();
-    return MAGNETISM_EDGE_LEFT;
-  }
-
-  Range GetPrimaryRange(const gfx::Rect& bounds) const {
-    switch (edge_) {
-      case MAGNETISM_EDGE_TOP:
-      case MAGNETISM_EDGE_BOTTOM:
-        return Range(bounds.y(), bounds.bottom());
-      case MAGNETISM_EDGE_LEFT:
-      case MAGNETISM_EDGE_RIGHT:
-        return Range(bounds.x(), bounds.right());
-    }
-    NOTREACHED();
-    return Range();
-  }
-
-  Range GetSecondaryRange(const gfx::Rect& bounds) const {
-    switch (edge_) {
-      case MAGNETISM_EDGE_TOP:
-      case MAGNETISM_EDGE_BOTTOM:
-        return Range(bounds.x(), bounds.right());
-      case MAGNETISM_EDGE_LEFT:
-      case MAGNETISM_EDGE_RIGHT:
-        return Range(bounds.y(), bounds.bottom());
-    }
-    NOTREACHED();
-    return Range();
-  }
-
-  static bool RangesIntersect(const Range& r1, const Range& r2) {
-    return r2.first < r1.second && r2.second > r1.first;
-  }
-
-  // The bounds of window.
-  const gfx::Rect bounds_;
-
-  // The edge this matcher checks.
-  const MagnetismEdge edge_;
-
-  // Visible ranges of the edge. Initialized with GetSecondaryRange() and
-  // updated as ShouldAttach() is invoked. When empty the edge is completely
-  // obscured by other bounds.
-  Ranges ranges_;
-
-  DISALLOW_COPY_AND_ASSIGN(MagnetismEdgeMatcher);
-};
-
-enum SecondaryMagnetismEdge {
-  SECONDARY_MAGNETISM_EDGE_LEADING,
-  SECONDARY_MAGNETISM_EDGE_TRAILING,
-  SECONDARY_MAGNETISM_EDGE_NONE,
-};
-
-// Used to identify a matched edge. |primary_edge| is relative to the source and
-// indicates the edge the two are to share. For example, if |primary_edge| is
-// MAGNETISM_EDGE_RIGHT then the right edge of the source should snap to to the
-// left edge of the target. |secondary_edge| indicates one of the edges along
-// the opposite axis should should also be aligned. For example, if
-// |primary_edge| is MAGNETISM_EDGE_RIGHT and |secondary_edge| is
-// SECONDARY_MAGNETISM_EDGE_LEADING then the source should snap to the left top
-// corner of the target.
-struct MatchedEdge {
-  MagnetismEdge primary_edge;
-  SecondaryMagnetismEdge secondary_edge;
-};
-
-// MagnetismMatcher is used to test if a window should snap to another window.
-// To use MagnetismMatcher do the following:
-// . Create it with the bounds of the window being dragged.
-// . Iterate over the child windows checking if the window being dragged should
-//   attach to it using ShouldAttach().
-// . Use AreEdgesObscured() to test if no other windows can match (because all
-//   edges are completely obscured).
-class ASH_EXPORT MagnetismMatcher {
- public:
-  static const int kMagneticDistance;
-
-  // |edges| is a bitmask of MagnetismEdges to match against.
-  MagnetismMatcher(const gfx::Rect& bounds, uint32_t edges);
-  ~MagnetismMatcher();
-
-  // Returns true if |bounds| is close enough to the initial bounds that the two
-  // should be attached. If true is returned |edge| is set to indicates how the
-  // two should snap together. See description of MatchedEdge for details.
-  bool ShouldAttach(const gfx::Rect& bounds, MatchedEdge* edge);
-
-  // Returns true if no other matches are possible.
-  bool AreEdgesObscured() const;
-
- private:
-  // Sets |secondary_edge| based on whether the secondary edges should snap.
-  void AttachToSecondaryEdge(const gfx::Rect& bounds,
-                             MagnetismEdge edge,
-                             SecondaryMagnetismEdge* secondary_edge) const;
-
-  // The edges to match against.
-  const int32_t edges_;
-
-  std::vector<std::unique_ptr<MagnetismEdgeMatcher>> matchers_;
-
-  DISALLOW_COPY_AND_ASSIGN(MagnetismMatcher);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_WM_WORKSPACE_MAGNETISM_MATCHER_H_