axmol/core/ui/UILayout.h

/****************************************************************************
Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
Copyright (c) Bytedance Inc.

https://axmolengine.github.io/

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#ifndef __LAYOUT_H__
#define __LAYOUT_H__

#include "ui/UIWidget.h"
#include "ui/GUIExport.h"
#include "renderer/CustomCommand.h"
#include "renderer/GroupCommand.h"
#include "renderer/CallbackCommand.h"

/**
 * @addtogroup ui
 * @{
 */
NS_AX_BEGIN

class DrawNode;
class LayerColor;
class LayerGradient;
class StencilStateManager;
struct AX_DLL ResourceData;

namespace ui
{

class LayoutManager;
class Scale9Sprite;

/**
 *@brief Layout interface for creating LayoutManger and do actual layout.
 * @js NA
 */
class AX_GUI_DLL LayoutProtocol
{
public:
    /**
     *@brief Default constructor.
     */
    LayoutProtocol() {}
    /**
     *@brief Default destructor.
     */
    virtual ~LayoutProtocol() {}

    /**
     * @brief Create a custom layout manager.
     *
     * @return A LayoutManager descendants instance.
     */
    virtual LayoutManager* createLayoutManager() = 0;

    /**
     * @brief Return the content size of layout.
     *
     * @return A content size in Vec2.
     */
    virtual Vec2 getLayoutContentSize() const = 0;

    /**
     * @brief Get all elements of the layout.
     *
     * @return A vector of Node pointers.
     */
    virtual const Vector<Node*>& getLayoutElements() const = 0;

    /**
     * @brief The main function to do the layout job.
     *  Different layout manager should implement its own layout algorithm.
     *
     */
    virtual void doLayout() = 0;
};

/**
 *@brief A container for holding a few child widgets.
 *
 * The child widgets could be rearranged according to the layout type and it also enables clipping, set background image
 *and color.
 *
 * There are mainly four types of layout:
 * - Absolute layout: This the default layout type, child elements are arranged by their absolute position.
 * - Horizontal layout: child elements are arranged horizontally.
 * - Vertical layout: child elements are arranged vertically.
 * - Relative layout: child elements are arranged relative to certain rules.
 *
 */
class AX_GUI_DLL Layout : public Widget, public LayoutProtocol
{

    DECLARE_CLASS_GUI_INFO

public:
    /**
     * Layout type, default is ABSOLUTE.
     */
    enum class Type
    {
        ABSOLUTE,
        VERTICAL,
        HORIZONTAL,
        RELATIVE,
        CENTER_VERTICAL,
        CENTER_HORIZONTAL,
    };

    /**
     * Clipping Type, default is STENCIL.
     */
    enum class ClippingType
    {
        STENCIL,
        SCISSOR
    };

    /**
     * Background color type, default is NONE.
     */
    enum class BackGroundColorType
    {
        NONE,
        SOLID,
        GRADIENT
    };

    /**
     * Default constructor
     * @js ctor
     * @lua new
     */
    Layout();

    /**
     * Default destructor
     * @js NA
     * @lua NA
     */
    virtual ~Layout();

    /**
     * Create a empty layout.
     */
    static Layout* create();

    /**
     * Sets a background image for layout.
     *
     * @param fileName image file path.
     * @param texType @see TextureResType.
     */
    void setBackGroundImage(std::string_view fileName, TextureResType texType = TextureResType::LOCAL);

    /**
     * Sets a background image capinsets for layout, it only affects the scale9 enabled background image
     *
     * @param capInsets  The capInsets in Rect.
     *
     */
    void setBackGroundImageCapInsets(const Rect& capInsets);

    /**
     * Query background image's capInsets size.
     *@return The background image capInsets.
     */
    const Rect& getBackGroundImageCapInsets() const;

    /**
     * Sets Color Type for layout's background
     *
     * @param type   @see `BackGroundColorType`
     */
    void setBackGroundColorType(BackGroundColorType type);

    /**
     * Query the layout's background color type.
     *@return The layout's background color type.
     */
    BackGroundColorType getBackGroundColorType() const;

    /**
     * Enable background image scale9 rendering.
     *
     * @param enabled  True means enable scale9 rendering for background image, false otherwise.
     */
    void setBackGroundImageScale9Enabled(bool enabled);

    /**
     * Query background image scale9 enable status.
     *@return Whether background image is scale9 enabled or not.
     */
    bool isBackGroundImageScale9Enabled() const;

    /**
     * Set background color for layout
     * The color only applies to layout when it's color type is BackGroundColorType::SOLIDE
     *
     * @param color Color in Color3B.
     */
    void setBackGroundColor(const Color3B& color);

    /**
     * Query the layout's background color.
     *@return Background color in Color3B.
     */
    const Color3B& getBackGroundColor() const;

    /**
     * Set start and end background color for layout.
     * This setting only take effect when the layout's  color type is BackGroundColorType::GRADIENT
     *
     * @param startColor Color value in Color3B.
     * @param endColor Color value in Color3B.
     */
    void setBackGroundColor(const Color3B& startColor, const Color3B& endColor);

    /**
     * Get the gradient background start color.
     *@return  Gradient background start color value.
     */
    const Color3B& getBackGroundStartColor() const;

    /**
     * Get the gradient background end color.
     * @return Gradient background end color value.
     */
    const Color3B& getBackGroundEndColor() const;

    /**
     * Sets background color opacity of layout.
     *
     * @param opacity The opacity in `GLubyte`.
     */
    void setBackGroundColorOpacity(uint8_t opacity);

    /**
     * Get the layout's background color opacity.
     *@return Background color opacity value.
     */
    uint8_t getBackGroundColorOpacity() const;

    /**
     * Sets background color vector for layout.
     * This setting only take effect when layout's color type is BackGroundColorType::GRADIENT
     *
     * @param vector The color vector in `Vec2`.
     */
    void setBackGroundColorVector(const Vec2& vector);

    /**
     * Get the layout's background color vector.
     *@return Background color vector.
     */
    const Vec2& getBackGroundColorVector() const;

    /**
     * Set layout's background image color.
     *@param color Background color value in `Color3B`.
     */
    void setBackGroundImageColor(const Color3B& color);

    /**
     * Set opacity of background image.
     *@param opacity Background image opacity in GLubyte.
     */
    void setBackGroundImageOpacity(uint8_t opacity);

    /**
     * Get color of layout's background image.
     *@return Layout's background image color.
     */
    const Color3B& getBackGroundImageColor() const;

    /**
     * Get the opacity of layout's background image.
     * @return The opacity of layout's background image.
     */
    uint8_t getBackGroundImageOpacity() const;

    /**
     * Remove the background image of layout.
     */
    void removeBackGroundImage();

    /**
     * Gets background image texture size.
     *
     * @return background image texture size.
     */
    const Vec2& getBackGroundImageTextureSize() const;

    /**
     * Toggle layout clipping.
     *
     * If you do need clipping, you pass true to this function.
     *
     * @param enabled Pass true to enable clipping, false otherwise.
     */
    virtual void setClippingEnabled(bool enabled);

    /**
     * Change the clipping type of layout.
     * On default, the clipping type is `ClippingType::STENCIL`.
     * @see `ClippingType`
     *@param type The clipping type of layout.
     */
    void setClippingType(ClippingType type);

    /**
     *
     * @see `setClippingType(ClippingType)`
     */
    ClippingType getClippingType() const;

    /**
     * Gets if layout is clipping enabled.
     *
     * @return if layout is clipping enabled.
     */
    virtual bool isClippingEnabled() const;

    /**
     * Returns the "class name" of widget.
     */
    virtual std::string getDescription() const override;

    /**
     * Change the layout type.
     *@param type Layout type.
     */
    virtual void setLayoutType(Type type);

    /**
     * Query layout type.
     *@return Get the layout type.
     */
    virtual Type getLayoutType() const;

    virtual void addChild(Node* child) override;
    virtual void addChild(Node* child, int localZOrder) override;
    /**
     * Adds a child to the container with z order and tag
     *
     * If the child is added to a 'running' node, then 'onEnter' and 'onEnterTransitionDidFinish' will be called
     * immediately.
     *
     * @param child     A child node
     * @param localZOrder    Z order for drawing priority. Please refer to setLocalZOrder(int)
     * @param tag       A integer to identify the node easily. Please refer to setTag(int)
     */
    virtual void addChild(Node* child, int localZOrder, int tag) override;
    virtual void addChild(Node* child, int localZOrder, std::string_view name) override;

    virtual void visit(Renderer* renderer, const Mat4& parentTransform, uint32_t parentFlags) override;

    virtual void removeChild(Node* child, bool cleanup = true) override;

    /**
     * Removes all children from the container with a cleanup.
     *
     * @see `removeAllChildrenWithCleanup(bool)`
     */
    virtual void removeAllChildren() override;
    /**
     * Removes all children from the container, and do a cleanup to all running actions depending on the cleanup
     * parameter.
     *
     * @param cleanup   true if all running actions on all children nodes should be cleanup, false otherwise.
     * @js removeAllChildren
     * @lua removeAllChildren
     */
    virtual void removeAllChildrenWithCleanup(bool cleanup) override;

    /**
     * force refresh widget layout
     */
    virtual void forceDoLayout();

    /**
     * request to refresh widget layout
     */
    virtual void requestDoLayout();

    /**
     * @lua NA
     */
    virtual void onEnter() override;

    /**
     * @lua NA
     */
    virtual void onExit() override;

    virtual void setGlobalZOrder(float globalZOrder) override;

    /**
     * If a layout is loop focused which means that the focus movement will be inside the layout
     *@param loop  pass true to let the focus movement loop inside the layout
     */
    void setLoopFocus(bool loop);

    /**
     *@return If focus loop is enabled, then it will return true, otherwise it returns false. The default value is
     *false.
     */
    bool isLoopFocus() const;

    /**
     *@param pass To specify whether the layout pass its focus to its child
     */
    void setPassFocusToChild(bool pass);

    /**
     * @return To query whether the layout will pass the focus to its children or not. The default value is true
     */
    bool isPassFocusToChild() const;

    /**
     *  When a widget is in a layout, you could call this method to get the next focused widget within a specified
     *direction. If the widget is not in a layout, it will return itself
     *@param direction the direction to look for the next focused widget in a layout
     *@param current  the current focused widget
     *@return the next focused widget in a layout
     */
    virtual Widget* findNextFocusedWidget(FocusDirection direction, Widget* current) override;

    /**
     * To specify a user-defined functor to decide which child widget of the layout should get focused
     * @param FocusDirection the finding direction
     * @param this previous focused widget
     * @return return the index of widget in the layout
     */
    std::function<int(FocusDirection, Widget*)> onPassFocusToChild;

    /**
     * Override function. Set camera mask, the node is visible by the camera whose camera flag & node's camera mask is
     * true.
     * @param mask Mask being set
     * @param applyChildren If true call this function recursively from this node to its children.
     */
    virtual void setCameraMask(unsigned short mask, bool applyChildren = true) override;

    ResourceData getRenderFile();

    // override "init" method of widget.
    virtual bool init() override;

protected:
    // override "onSizeChanged" method of widget.
    virtual void onSizeChanged() override;

    // init background image renderer.
    void addBackGroundImage();

    void supplyTheLayoutParameterLackToChild(Widget* child);
    virtual Widget* createCloneInstance() override;
    virtual void copySpecialProperties(Widget* model) override;
    virtual void copyClonedWidgetChildren(Widget* model) override;

    void stencilClippingVisit(Renderer* renderer, const Mat4& parentTransform, uint32_t parentFlags);
    void scissorClippingVisit(Renderer* renderer, const Mat4& parentTransform, uint32_t parentFlags);

    void setStencilClippingSize(const Vec2& size);
    const Rect& getClippingRect();

    virtual void doLayout() override;
    virtual LayoutManager* createLayoutManager() override;
    virtual Vec2 getLayoutContentSize() const override;
    virtual const Vector<Node*>& getLayoutElements() const override;

    // clipping

    void onBeforeVisitScissor();
    void onAfterVisitScissor();
    void updateBackGroundImageColor();
    void updateBackGroundImageOpacity();
    void updateBackGroundImageRGBA();

    /**
     *get the content size of the layout, it will accumulate all its children's content size
     */
    Vec2 getLayoutAccumulatedSize() const;

    /**
     * When the layout get focused, it the layout pass the focus to its child, it will use this method to determine
     *which child will get the focus.  The current algorithm to determine which child will get focus is
     *nearest-distance-priority algorithm
     *@param direction The next focused widget direction
     *@return The index of child widget in the container
     */
    int findNearestChildWidgetIndex(FocusDirection direction, Widget* baseWidget);

    /**
     * When the layout get focused, it the layout pass the focus to its child, it will use this method to determine
     *which child will get the focus.  The current algorithm to determine which child will get focus is
     *farthest-distance-priority algorithm
     *@param direction The next focused widget direction
     *@return The index of child widget in the container
     */
    int findFarthestChildWidgetIndex(FocusDirection direction, Widget* baseWidget);

    /**
     * calculate the nearest distance between the baseWidget and the children of the layout
     *@param the base widget which will be used to calculate the distance between the layout's children and itself
     *@return return the nearest distance between the baseWidget and the layout's children
     */
    float calculateNearestDistance(Widget* baseWidget);

    /**
     * calculate the farthest distance between the baseWidget and the children of the layout
     *@param the base widget which will be used to calculate the distance between the layout's children and itself
     *@return return the farthest distance between the baseWidget and the layout's children
     */

    float calculateFarthestDistance(Widget* baseWidget);

    /**
     *  when a layout pass the focus to it's child, use this method to determine which algorithm to use, nearest or
     * farthest distance algorithm or not
     */
    void findProperSearchingFunctor(FocusDirection dir, Widget* baseWidget);

    /**
     * find the first non-layout widget in this layout
     */
    Widget* findFirstNonLayoutWidget();

    /**
     * find the first focus enabled widget index in the layout, it will recursive searching the child widget
     */
    int findFirstFocusEnabledWidgetIndex();

    /**
     * find a focus enabled child Widget in the layout by index
     */
    Widget* findFocusEnabledChildWidgetByIndex(ssize_t index);

    /**
     * get the center point of a widget in world space
     */
    Vec2 getWorldCenterPoint(Widget* node) const;

    /**
     * this method is called internally by nextFocusedWidget. When the dir is Right/Down, then this method will be
     *called
     *@param direction  the direction.
     *@param current  the current focused widget
     *@return the next focused widget
     */
    Widget* getNextFocusedWidget(FocusDirection direction, Widget* current);

    /**
     * this method is called internally by nextFocusedWidget. When the dir is Left/Up, then this method will be called
     *@param direction  the direction.
     *@param current  the current focused widget
     *@return the next focused widget
     */
    Widget* getPreviousFocusedWidget(FocusDirection direction, Widget* current);

    /**
     * find the nth element in the _children array. Only the Widget descendant object will be returned
     *@param index  The index of a element in the _children array
     */
    Widget* getChildWidgetByIndex(ssize_t index) const;
    /**
     * whether it is the last element according to all their parents
     */
    bool isLastWidgetInContainer(Widget* widget, FocusDirection direction) const;

    /**Lookup any parent widget with a layout type as the direction,
     * if the layout is loop focused, then return true, otherwise
     * It returns false
     */
    bool isWidgetAncestorSupportLoopFocus(Widget* widget, FocusDirection direction) const;

    /**
     * pass the focus to the layout's next focus enabled child
     */
    Widget* passFocusToChild(FocusDirection direction, Widget* current);

    /**
     * If there are no focus enabled child in the layout, it will return false, otherwise it returns true
     */
    bool checkFocusEnabledChild() const;

protected:
    // background
    bool _backGroundScale9Enabled;
    Scale9Sprite* _backGroundImage;
    std::string _backGroundImageFileName;
    Rect _backGroundImageCapInsets;
    BackGroundColorType _colorType;
    TextureResType _bgImageTexType;
    Vec2 _backGroundImageTextureSize;
    Color3B _backGroundImageColor;
    uint8_t _backGroundImageOpacity;

    LayerColor* _colorRender;
    LayerGradient* _gradientRender;
    Color3B _cColor;
    Color3B _gStartColor;
    Color3B _gEndColor;
    Vec2 _alongVector;
    uint8_t _cOpacity;

    // clipping
    bool _clippingEnabled;
    Type _layoutType;
    ClippingType _clippingType;
    DrawNode* _clippingStencil;
    bool _scissorOldState;
    Rect _clippingOldRect;
    Rect _clippingRect;
    Layout* _clippingParent;
    bool _clippingRectDirty;

    // clipping
    StencilStateManager* _stencilStateManager;

    //CallbackCommand _beforeVisitCmdStencil;
    //CallbackCommand _afterDrawStencilCmd;
    //CallbackCommand _afterVisitCmdStencil;
    //CallbackCommand _beforeVisitCmdScissor;
    //CallbackCommand _afterVisitCmdScissor;

    bool _doLayoutDirty;
    bool _isInterceptTouch;

    // whether enable loop focus or not
    bool _loopFocus;
    // on default, it will pass the focus to the next nearest widget
    bool _passFocusToChild;
    // when finding the next focused widget, use this variable to pass focus between layout & widget
    bool _isFocusPassing;
};

}  // namespace ui
NS_AX_END
// end of ui group
/// @}
#endif /* defined(__Layout__) */