/* * Copyright (c) 2018-2020, Andreas Kling * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include namespace GUI { ScrollableWidget::ScrollableWidget() { m_vertical_scrollbar = add(Orientation::Vertical); m_vertical_scrollbar->set_step(4); m_vertical_scrollbar->on_change = [this](int) { did_scroll(); update(); }; m_horizontal_scrollbar = add(Orientation::Horizontal); m_horizontal_scrollbar->set_step(4); m_horizontal_scrollbar->set_big_step(30); m_horizontal_scrollbar->on_change = [this](int) { did_scroll(); update(); }; m_corner_widget = add(); m_corner_widget->set_fill_with_background_color(true); } ScrollableWidget::~ScrollableWidget() { } void ScrollableWidget::mousewheel_event(MouseEvent& event) { if (!m_scrollbars_enabled) { event.ignore(); return; } // FIXME: The wheel delta multiplier should probably come from... somewhere? vertical_scrollbar().set_value(vertical_scrollbar().value() + event.wheel_delta() * 20); } void ScrollableWidget::custom_layout() { auto inner_rect = frame_inner_rect_for_size(size()); int height_wanted_by_horizontal_scrollbar = m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->preferred_size().height() : 0; int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->preferred_size().width() : 0; m_vertical_scrollbar->set_relative_rect( inner_rect.right() + 1 - m_vertical_scrollbar->preferred_size().width(), inner_rect.top(), m_vertical_scrollbar->preferred_size().width(), inner_rect.height() - height_wanted_by_horizontal_scrollbar); m_horizontal_scrollbar->set_relative_rect( inner_rect.left(), inner_rect.bottom() + 1 - m_horizontal_scrollbar->preferred_size().height(), inner_rect.width() - width_wanted_by_vertical_scrollbar, m_horizontal_scrollbar->preferred_size().height()); m_corner_widget->set_visible(m_vertical_scrollbar->is_visible() && m_horizontal_scrollbar->is_visible()); if (m_corner_widget->is_visible()) { Gfx::Rect corner_rect { m_horizontal_scrollbar->relative_rect().right() + 1, m_vertical_scrollbar->relative_rect().bottom() + 1, width_occupied_by_vertical_scrollbar(), height_occupied_by_horizontal_scrollbar() }; m_corner_widget->set_relative_rect(corner_rect); } } void ScrollableWidget::resize_event(ResizeEvent& event) { Frame::resize_event(event); update_scrollbar_ranges(); } Gfx::Size ScrollableWidget::available_size() const { int available_width = frame_inner_rect().width() - m_size_occupied_by_fixed_elements.width() - width_occupied_by_vertical_scrollbar(); int available_height = frame_inner_rect().height() - m_size_occupied_by_fixed_elements.height() - height_occupied_by_horizontal_scrollbar(); return { available_width, available_height }; } void ScrollableWidget::update_scrollbar_ranges() { auto available_size = this->available_size(); int excess_height = max(0, m_content_size.height() - available_size.height()); m_vertical_scrollbar->set_range(0, excess_height); if (should_hide_unnecessary_scrollbars()) m_vertical_scrollbar->set_visible(excess_height > 0); int excess_width = max(0, m_content_size.width() - available_size.width()); m_horizontal_scrollbar->set_range(0, excess_width); if (should_hide_unnecessary_scrollbars()) m_horizontal_scrollbar->set_visible(excess_width > 0); m_vertical_scrollbar->set_big_step(visible_content_rect().height() - m_vertical_scrollbar->step()); } void ScrollableWidget::set_content_size(const Gfx::Size& size) { if (m_content_size == size) return; m_content_size = size; update_scrollbar_ranges(); } void ScrollableWidget::set_size_occupied_by_fixed_elements(const Gfx::Size& size) { if (m_size_occupied_by_fixed_elements == size) return; m_size_occupied_by_fixed_elements = size; update_scrollbar_ranges(); } int ScrollableWidget::height_occupied_by_horizontal_scrollbar() const { return m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->height() : 0; } int ScrollableWidget::width_occupied_by_vertical_scrollbar() const { return m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->width() : 0; } Gfx::Rect ScrollableWidget::visible_content_rect() const { return { m_horizontal_scrollbar->value(), m_vertical_scrollbar->value(), min(m_content_size.width(), frame_inner_rect().width() - width_occupied_by_vertical_scrollbar() - m_size_occupied_by_fixed_elements.width()), min(m_content_size.height(), frame_inner_rect().height() - height_occupied_by_horizontal_scrollbar() - m_size_occupied_by_fixed_elements.height()) }; } void ScrollableWidget::scroll_into_view(const Gfx::Rect& rect, Orientation orientation) { if (orientation == Orientation::Vertical) return scroll_into_view(rect, false, true); return scroll_into_view(rect, true, false); } void ScrollableWidget::scroll_into_view(const Gfx::Rect& rect, bool scroll_horizontally, bool scroll_vertically) { auto visible_content_rect = this->visible_content_rect(); if (visible_content_rect.contains(rect)) return; if (scroll_vertically) { if (rect.top() < visible_content_rect.top()) m_vertical_scrollbar->set_value(rect.top()); else if (rect.bottom() > visible_content_rect.bottom()) m_vertical_scrollbar->set_value(rect.bottom() - visible_content_rect.height()); } if (scroll_horizontally) { if (rect.left() < visible_content_rect.left()) m_horizontal_scrollbar->set_value(rect.left()); else if (rect.right() > visible_content_rect.right()) m_horizontal_scrollbar->set_value(rect.right() - visible_content_rect.width()); } } void ScrollableWidget::set_scrollbars_enabled(bool scrollbars_enabled) { if (m_scrollbars_enabled == scrollbars_enabled) return; m_scrollbars_enabled = scrollbars_enabled; m_vertical_scrollbar->set_visible(m_scrollbars_enabled); m_horizontal_scrollbar->set_visible(m_scrollbars_enabled); m_corner_widget->set_visible(m_scrollbars_enabled); } void ScrollableWidget::scroll_to_top() { scroll_into_view({ 0, 0, 1, 1 }, Orientation::Vertical); } void ScrollableWidget::scroll_to_bottom() { scroll_into_view({ 0, content_height(), 1, 1 }, Orientation::Vertical); } Gfx::Rect ScrollableWidget::widget_inner_rect() const { auto rect = frame_inner_rect(); rect.set_width(rect.width() - width_occupied_by_vertical_scrollbar()); rect.set_height(rect.height() - height_occupied_by_horizontal_scrollbar()); return rect; } Gfx::Point ScrollableWidget::to_content_position(const Gfx::Point& widget_position) const { auto content_position = widget_position; content_position.move_by(horizontal_scrollbar().value(), vertical_scrollbar().value()); content_position.move_by(-frame_thickness(), -frame_thickness()); return content_position; } Gfx::Point ScrollableWidget::to_widget_position(const Gfx::Point& content_position) const { auto widget_position = content_position; widget_position.move_by(-horizontal_scrollbar().value(), -vertical_scrollbar().value()); widget_position.move_by(frame_thickness(), frame_thickness()); return widget_position; } }