blob: f24e9b1dfc7f264dbfa58bbced2b4b05137a69e2 [file] [log] [blame]
// 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.
#include "ash/ash_export.h"
#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "base/logging.h"
#include "base/macros.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/rect.h"
namespace aura {
class Window;
namespace ash {
class ASH_EXPORT MagnificationController {
enum ScrollDirection {
virtual ~MagnificationController() {}
// Factor of magnification scale. For example, when this value is 1.189, scale
// value will be changed x1.000, x1.189, x1.414, x1.681, x2.000, ...
// Note: this value is 2.0 ^ (1 / 4).
static constexpr float kMagnificationScaleFactor = 1.18920712f;
// Creates a new MagnificationController. The caller takes ownership of the
// returned object.
static MagnificationController* CreateInstance();
// Enables (or disables if |enabled| is false) screen magnifier feature.
virtual void SetEnabled(bool enabled) = 0;
// Returns if the screen magnifier is enabled or not.
virtual bool IsEnabled() const = 0;
// Enables or disables the feature for keeping the text input focus centered.
virtual void SetKeepFocusCentered(bool keep_focus_centered) = 0;
// Returns true if magnifier will keep the focus centered in screen for text
// input.
virtual bool KeepFocusCentered() const = 0;
// Sets the magnification ratio. 1.0f means no magnification.
virtual void SetScale(float scale, bool animate) = 0;
// Returns the current magnification ratio.
virtual float GetScale() const = 0;
// Set the top-left point of the magnification window.
virtual void MoveWindow(int x, int y, bool animate) = 0;
virtual void MoveWindow(const gfx::Point& point, bool animate) = 0;
// Returns the current top-left point of the magnification window.
virtual gfx::Point GetWindowPosition() const = 0;
virtual void SetScrollDirection(ScrollDirection direction) = 0;
// Returns the view port(i.e. the current visible window)'s Rect in root
// window coordinates.
virtual gfx::Rect GetViewportRect() const = 0;
// Follows the focus on web page for non-editable controls.
virtual void HandleFocusedNodeChanged(
bool is_editable_node,
const gfx::Rect& node_bounds_in_screen) = 0;
// Returns |point_of_interest_| in MagnificationControllerImpl. This is
// the internal variable to stores the last mouse cursor (or last touched)
// location. This method is only for test purpose.
virtual gfx::Point GetPointOfInterestForTesting() = 0;
// Returns true if magnifier is still on animation for moving viewport.
// This is only used for testing purpose.
virtual bool IsOnAnimationForTesting() const = 0;
// Disables the delay for moving magnifier window in testing mode.
virtual void DisableMoveMagnifierDelayForTesting() = 0;
// Switch the magnified root window to |new_root_window|. This does following:
// - Unzoom the current root_window.
// - Zoom the given new root_window |new_root_window|.
// - Switch the target window from current window to |new_root_window|.
virtual void SwitchTargetRootWindow(aura::Window* new_root_window,
bool redraw_original_root) = 0;
MagnificationController() {}
FRIEND_TEST_ALL_PREFIXES(MagnificationControllerTest, AdjustScaleFromScroll);
// Calculates the new scale if it were to be adjusted exponentially by the
// given |linear_offset|. This allows linear changes in scroll offset
// to have exponential changes on the scale, so that as the user zooms in,
// they appear to zoom faster through higher resolutions. This also has the
// effect that whether the user moves their fingers quickly or slowly on
// the trackpad (changing the number of events fired), the resulting zoom
// will only depend on the distance their fingers traveled.
// |linear_offset| should generally be between 0 and 1, to result in a set
// scale between |kNonMagnifiedScale| and |kMaxMagnifiedScale|.
// The resulting scale should be an exponential of the form
// y = M * x ^ 2 + c, where y is the resulting scale, M is the difference
// between |kNonMagnifiedScale| and |kMaxMagnifiedScale|, and c is
// |kNonMagnifiedScale| scale. This creates a mapping from |linear_offset|
// in (0, 1) to scale in (min, max).
// Protected so it may be accessed by classes who inherit from this.
float GetScaleFromScroll(float linear_offset);
} // namespace ash