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// Copyright (c) 2011 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 "ui/views/controls/scrollbar/base_scroll_bar_thumb.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/views/controls/scrollbar/base_scroll_bar.h"
namespace {
// The distance the mouse can be dragged outside the bounds of the thumb during
// dragging before the scrollbar will snap back to its regular position.
static const int kScrollThumbDragOutSnap = 100;
}
namespace views {
BaseScrollBarThumb::BaseScrollBarThumb(BaseScrollBar* scroll_bar)
: scroll_bar_(scroll_bar),
drag_start_position_(-1),
mouse_offset_(-1),
state_(CustomButton::STATE_NORMAL) {
}
BaseScrollBarThumb::~BaseScrollBarThumb() {
}
void BaseScrollBarThumb::SetSize(int size) {
// Make sure the thumb is never sized smaller than its minimum possible
// display size.
gfx::Size prefsize = GetPreferredSize();
size = std::max(size, scroll_bar_->IsHorizontal() ? prefsize.width() :
prefsize.height());
gfx::Rect thumb_bounds = bounds();
if (scroll_bar_->IsHorizontal()) {
thumb_bounds.set_width(size);
} else {
thumb_bounds.set_height(size);
}
SetBoundsRect(thumb_bounds);
}
int BaseScrollBarThumb::GetSize() const {
if (scroll_bar_->IsHorizontal())
return width();
return height();
}
void BaseScrollBarThumb::SetPosition(int position) {
gfx::Rect thumb_bounds = bounds();
gfx::Rect track_bounds = scroll_bar_->GetTrackBounds();
if (scroll_bar_->IsHorizontal()) {
thumb_bounds.set_x(track_bounds.x() + position);
} else {
thumb_bounds.set_y(track_bounds.y() + position);
}
SetBoundsRect(thumb_bounds);
}
int BaseScrollBarThumb::GetPosition() const {
gfx::Rect track_bounds = scroll_bar_->GetTrackBounds();
if (scroll_bar_->IsHorizontal())
return x() - track_bounds.x();
return y() - track_bounds.y();
}
void BaseScrollBarThumb::OnMouseEntered(const ui::MouseEvent& event) {
SetState(CustomButton::STATE_HOVERED);
}
void BaseScrollBarThumb::OnMouseExited(const ui::MouseEvent& event) {
SetState(CustomButton::STATE_NORMAL);
}
bool BaseScrollBarThumb::OnMousePressed(const ui::MouseEvent& event) {
mouse_offset_ = scroll_bar_->IsHorizontal() ? event.x() : event.y();
drag_start_position_ = GetPosition();
SetState(CustomButton::STATE_PRESSED);
return true;
}
bool BaseScrollBarThumb::OnMouseDragged(const ui::MouseEvent& event) {
// If the user moves the mouse more than |kScrollThumbDragOutSnap| outside
// the bounds of the thumb, the scrollbar will snap the scroll back to the
// point it was at before the drag began.
if (scroll_bar_->IsHorizontal()) {
if ((event.y() < y() - kScrollThumbDragOutSnap) ||
(event.y() > (y() + height() + kScrollThumbDragOutSnap))) {
scroll_bar_->ScrollToThumbPosition(drag_start_position_, false);
return true;
}
} else {
if ((event.x() < x() - kScrollThumbDragOutSnap) ||
(event.x() > (x() + width() + kScrollThumbDragOutSnap))) {
scroll_bar_->ScrollToThumbPosition(drag_start_position_, false);
return true;
}
}
if (scroll_bar_->IsHorizontal()) {
int thumb_x = event.x() - mouse_offset_;
if (base::i18n::IsRTL())
thumb_x *= -1;
scroll_bar_->ScrollToThumbPosition(GetPosition() + thumb_x, false);
} else {
int thumb_y = event.y() - mouse_offset_;
scroll_bar_->ScrollToThumbPosition(GetPosition() + thumb_y, false);
}
return true;
}
void BaseScrollBarThumb::OnMouseReleased(const ui::MouseEvent& event) {
SetState(HitTestPoint(event.location()) ?
CustomButton::STATE_HOVERED : CustomButton::STATE_NORMAL);
}
void BaseScrollBarThumb::OnMouseCaptureLost() {
SetState(CustomButton::STATE_HOVERED);
}
CustomButton::ButtonState BaseScrollBarThumb::GetState() const {
return state_;
}
void BaseScrollBarThumb::SetState(CustomButton::ButtonState state) {
if (state_ == state)
return;
CustomButton::ButtonState old_state = state_;
state_ = state;
scroll_bar_->OnThumbStateChanged(old_state, state);
SchedulePaint();
}
} // namespace views
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