ScrollablePanel.hpp

//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2025 Bruno Van de Velde (vdv_b@tgui.eu)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
//    you must not claim that you wrote the original software.
//    If you use this software in a product, an acknowledgment
//    in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
//    and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
 
#ifndef TGUI_SCROLLABLE_PANEL_HPP
#define TGUI_SCROLLABLE_PANEL_HPP
 
#include <TGUI/Widgets/Panel.hpp>
#include <TGUI/Widgets/Scrollbar.hpp>
#include <TGUI/Renderers/ScrollablePanelRenderer.hpp>
 
#if !TGUI_EXPERIMENTAL_USE_STD_MODULE
    #include <chrono>
#endif

 
TGUI_MODULE_EXPORT namespace tgui
{
    class TGUI_API ScrollablePanel : public Panel, public DualScrollbarChildInterface
    {
    public:
 
        using Ptr = std::shared_ptr<ScrollablePanel>; 
        using ConstPtr = std::shared_ptr<const ScrollablePanel>; 
 
        static constexpr const char StaticWidgetType[] = "ScrollablePanel"; 

        ScrollablePanel(const char* typeName = StaticWidgetType, bool initRenderer = true);

        ScrollablePanel(const ScrollablePanel& other);

        ScrollablePanel(ScrollablePanel&& other) noexcept;

        ScrollablePanel& operator= (const ScrollablePanel& other);

        ScrollablePanel& operator= (ScrollablePanel&& other) noexcept;

        TGUI_NODISCARD static ScrollablePanel::Ptr create(const Layout2d& size = {"100%", "100%"}, Vector2f contentSize = {0, 0});

        TGUI_NODISCARD static ScrollablePanel::Ptr copy(const ScrollablePanel::ConstPtr& panel);

        TGUI_NODISCARD ScrollablePanelRenderer* getSharedRenderer() override;
        TGUI_NODISCARD const ScrollablePanelRenderer* getSharedRenderer() const override;

        TGUI_NODISCARD ScrollablePanelRenderer* getRenderer() override;

        void setSize(const Layout2d& size) override;
        using Widget::setSize;

        TGUI_NODISCARD Vector2f getInnerSize() const override;

        TGUI_NODISCARD Vector2f getAbsolutePosition(Vector2f offset) const override;

        void add(const Widget::Ptr& widget, const String& widgetName = "") override;

        bool remove(const Widget::Ptr& widget) override;

        void removeAllWidgets() override;

        void setContentSize(Vector2f size);

        TGUI_NODISCARD Vector2f getContentSize() const;

        TGUI_NODISCARD Vector2f getContentOffset() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->getWidth() or getHorizontalScrollbar()->getWidth() instead") TGUI_NODISCARD float getScrollbarWidth() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->setPolicy(policy) instead") void setVerticalScrollbarPolicy(Scrollbar::Policy policy);

        TGUI_DEPRECATED("Use getVerticalScrollbar()->getPolicy() instead") TGUI_NODISCARD Scrollbar::Policy getVerticalScrollbarPolicy() const;

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->setPolicy(policy) instead") void setHorizontalScrollbarPolicy(Scrollbar::Policy policy);

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->getPolicy() instead") TGUI_NODISCARD Scrollbar::Policy getHorizontalScrollbarPolicy() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->setScrollAmount(scrollAmount) instead") void setVerticalScrollAmount(unsigned int scrollAmount);

        TGUI_DEPRECATED("Use getVerticalScrollbar()->getScrollAmount() instead") TGUI_NODISCARD unsigned int getVerticalScrollAmount() const;

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->setScrollAmount(scrollAmount) instead") void setHorizontalScrollAmount(unsigned int scrollAmount);

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->getScrollAmount() instead") TGUI_NODISCARD unsigned int getHorizontalScrollAmount() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->setValue(value) instead") void setVerticalScrollbarValue(unsigned int value);

        TGUI_DEPRECATED("Use getVerticalScrollbar()->getValue() instead") TGUI_NODISCARD unsigned int getVerticalScrollbarValue() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->getMaxValue() instead") TGUI_NODISCARD unsigned int getVerticalScrollbarMaxValue() const;

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->setValue(value) instead") void setHorizontalScrollbarValue(unsigned int value);

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->getValue() instead") TGUI_NODISCARD unsigned int getHorizontalScrollbarValue() const;

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->getMaxValue() instead") TGUI_NODISCARD unsigned int getHorizontalScrollbarMaxValue() const;

        TGUI_DEPRECATED("Use getVerticalScrollbar()->isShown() instead") TGUI_NODISCARD bool isVerticalScrollbarShown() const;

        TGUI_DEPRECATED("Use getHorizontalScrollbar()->isShown() instead") TGUI_NODISCARD bool isHorizontalScrollbarShown() const;

        TGUI_NODISCARD Widget::Ptr getWidgetAtPos(Vector2f pos, bool recursive) const override;

        bool leftMousePressed(Vector2f pos) override;

        void leftMouseReleased(Vector2f pos) override;

        void mouseMoved(Vector2f pos) override;

        bool scrolled(float delta, Vector2f pos, bool touch) override;

        void mouseNoLongerOnWidget() override;

        void leftMouseButtonNoLongerDown() override;

        // Shows the tool tip when the widget is located below the mouse.
        // Returns its tool tip or the tool tip from a child widget if the mouse is on top of the widget.
        // A nullptr is returned when the mouse is not on top of the widget or when the tool tip is empty.
        TGUI_NODISCARD Widget::Ptr askToolTip(Vector2f mousePos) override;

        void draw(BackendRenderTarget& target, RenderStates states) const override;

    protected:

        void rendererChanged(const String& property) override;

        TGUI_NODISCARD std::unique_ptr<DataIO::Node> save(SavingRenderersMap& renderers) const override;

        void load(const std::unique_ptr<DataIO::Node>& node, const LoadingRenderersMap& renderers) override;

        void scrollbarPolicyChanged(Orientation orientation) override;

        void scrollbarScrollAmountChanged(Orientation orientation) override;

        // Makes a copy of the widget
        TGUI_NODISCARD Widget::Ptr clone() const override;

    private:

        // Update the position, size and value of the scrollbars
        void updateScrollbars();

        // Find out what the most right and bottom positions are that are in use by the child widgets
        void recalculateMostBottomRightPosition();

        // Connect the position and size events to recalculate the bottom right position when a widget is updated
        void connectPositionAndSize(const Widget::Ptr& widget);

        // Disconnect the position and size events that were connected to keep track of widget changes
        void disconnectAllChildWidgets();

    protected:
 
        Vector2f         m_contentSize;
        Vector2f         m_mostBottomRightPosition;
 
        std::chrono::steady_clock::time_point m_lastSuccessfulScrollTime; // Timestamp of the last mouse wheel scroll event
        Vector2f m_lastSuccessfulScrollPos; // Mouse position at the last mouse wheel scroll event
 
        unsigned int m_verticalScrollAmount = 0;
        unsigned int m_horizontalScrollAmount = 0;
 
        bool m_verticalScrollbarWasVisibleOnSizeUpdate = false;
        bool m_horizontalScrollbarWasVisibleOnSizeUpdate = false;
        bool m_recalculatingSizeDuringUpdateScrollbars = false;
        bool m_stuckInUpdateScrollbars = false;
 
        std::unordered_map<Widget::Ptr, unsigned int> m_connectedPositionCallbacks;
        std::unordered_map<Widget::Ptr, unsigned int> m_connectedSizeCallbacks;

    };

}

 
#endif // TGUI_SCROLLABLE_PANEL_HPP