/*************************************************************************/
/*  rich_text_label.h                                                    */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
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/*************************************************************************/

#ifndef RICH_TEXT_LABEL_H
#define RICH_TEXT_LABEL_H

#include "scene/gui/scroll_bar.h"

class RichTextLabel : public Control {

	GDCLASS(RichTextLabel, Control);

public:
	enum Align {

		ALIGN_LEFT,
		ALIGN_CENTER,
		ALIGN_RIGHT,
		ALIGN_FILL
	};

	enum ListType {

		LIST_NUMBERS,
		LIST_LETTERS,
		LIST_DOTS
	};

	enum ItemType {

		ITEM_FRAME,
		ITEM_TEXT,
		ITEM_IMAGE,
		ITEM_NEWLINE,
		ITEM_FONT,
		ITEM_COLOR,
		ITEM_UNDERLINE,
		ITEM_ALIGN,
		ITEM_INDENT,
		ITEM_LIST,
		ITEM_TABLE,
		ITEM_META
	};

protected:
	static void _bind_methods();

private:
	struct Item;

	struct Line {

		Item *from;
		Vector<int> offset_caches;
		Vector<int> height_caches;
		Vector<int> ascent_caches;
		Vector<int> descent_caches;
		Vector<int> space_caches;
		int height_cache;
		int height_accum_cache;
		int char_count;
		int minimum_width;

		Line() {
			from = NULL;
			char_count = 0;
		}
	};

	struct Item {

		int index;
		Item *parent;
		ItemType type;
		List<Item *> subitems;
		List<Item *>::Element *E;
		int line;

		void _clear_children() {
			while (subitems.size()) {
				memdelete(subitems.front()->get());
				subitems.pop_front();
			}
		}

		Item() {
			parent = NULL;
			E = NULL;
			line = 0;
		}
		virtual ~Item() { _clear_children(); }
	};

	struct ItemFrame : public Item {

		int parent_line;
		bool cell;
		Vector<Line> lines;
		int first_invalid_line;
		ItemFrame *parent_frame;

		ItemFrame() {
			type = ITEM_FRAME;
			parent_frame = NULL;
			cell = false;
			parent_line = 0;
		}
	};

	struct ItemText : public Item {

		String text;
		ItemText() { type = ITEM_TEXT; }
	};

	struct ItemImage : public Item {

		Ref<Texture> image;
		ItemImage() { type = ITEM_IMAGE; }
	};

	struct ItemFont : public Item {

		Ref<Font> font;
		ItemFont() { type = ITEM_FONT; }
	};

	struct ItemColor : public Item {

		Color color;
		ItemColor() { type = ITEM_COLOR; }
	};

	struct ItemUnderline : public Item {

		ItemUnderline() { type = ITEM_UNDERLINE; }
	};

	struct ItemMeta : public Item {

		Variant meta;
		ItemMeta() { type = ITEM_META; }
	};

	struct ItemAlign : public Item {

		Align align;
		ItemAlign() { type = ITEM_ALIGN; }
	};

	struct ItemIndent : public Item {

		int level;
		ItemIndent() { type = ITEM_INDENT; }
	};

	struct ItemList : public Item {

		ListType list_type;
		ItemList() { type = ITEM_LIST; }
	};

	struct ItemNewline : public Item {

		int line; // FIXME: Overriding base's line ?
		ItemNewline() { type = ITEM_NEWLINE; }
	};

	struct ItemTable : public Item {

		struct Column {
			bool expand;
			int expand_ratio;
			int min_width;
			int width;
		};

		Vector<Column> columns;
		int total_width;
		ItemTable() { type = ITEM_TABLE; }
	};

	ItemFrame *main;
	Item *current;
	ItemFrame *current_frame;

	VScrollBar *vscroll;

	bool scroll_visible;
	bool scroll_follow;
	bool scroll_following;
	bool scroll_active;
	int scroll_w;
	bool updating_scroll;
	int current_idx;
	int visible_line_count;

	int tab_size;
	bool underline_meta;
	bool override_selected_font_color;

	Align default_align;

	ItemMeta *meta_hovering;
	Variant current_meta;

	void _invalidate_current_line(ItemFrame *p_frame);
	void _validate_line_caches(ItemFrame *p_frame);

	void _add_item(Item *p_item, bool p_enter = false, bool p_ensure_newline = false);
	void _remove_item(Item *p_item, const int p_line, const int p_subitem_line);

	struct ProcessState {

		int line_width;
	};

	enum ProcessMode {

		PROCESS_CACHE,
		PROCESS_DRAW,
		PROCESS_POINTER
	};

	struct Selection {

		Item *click;
		int click_char;

		Item *from;
		int from_char;
		Item *to;
		int to_char;

		bool active; // anything selected? i.e. from, to, etc. valid?
		bool enabled; // allow selections?
	};

	Selection selection;

	int visible_characters;
	float percent_visible;

	int _process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &y, int p_width, int p_line, ProcessMode p_mode, const Ref<Font> &p_base_font, const Color &p_base_color, const Point2i &p_click_pos = Point2i(), Item **r_click_item = NULL, int *r_click_char = NULL, bool *r_outside = NULL, int p_char_count = 0);
	void _find_click(ItemFrame *p_frame, const Point2i &p_click, Item **r_click_item = NULL, int *r_click_char = NULL, bool *r_outside = NULL);

	Ref<Font> _find_font(Item *p_item);
	int _find_margin(Item *p_item, const Ref<Font> &p_base_font);
	Align _find_align(Item *p_item);
	Color _find_color(Item *p_item, const Color &p_default_color);
	bool _find_underline(Item *p_item);
	bool _find_meta(Item *p_item, Variant *r_meta);

	void _update_scroll();
	void _scroll_changed(double);

	void _gui_input(Ref<InputEvent> p_event);
	Item *_get_next_item(Item *p_item, bool p_free = false);

	Rect2 _get_text_rect();

	bool use_bbcode;
	String bbcode;

	void _update_all_lines();

protected:
	void _notification(int p_what);

public:
	String get_text();
	void add_text(const String &p_text);
	void add_image(const Ref<Texture> &p_image);
	void add_newline();
	bool remove_line(const int p_line);
	void push_font(const Ref<Font> &p_font);
	void push_color(const Color &p_color);
	void push_underline();
	void push_align(Align p_align);
	void push_indent(int p_level);
	void push_list(ListType p_list);
	void push_meta(const Variant &p_meta);
	void push_table(int p_columns);
	void set_table_column_expand(int p_column, bool p_expand, int p_ratio = 1);
	int get_current_table_column() const;
	void push_cell();
	void pop();

	void clear();

	void set_offset(int p_pixel);

	void set_meta_underline(bool p_underline);
	bool is_meta_underlined() const;

	void set_override_selected_font_color(bool p_override_selected_font_color);
	bool is_overriding_selected_font_color() const;

	void set_scroll_active(bool p_active);
	bool is_scroll_active() const;

	void set_scroll_follow(bool p_follow);
	bool is_scroll_following() const;

	void set_tab_size(int p_spaces);
	int get_tab_size() const;

	bool search(const String &p_string, bool p_from_selection = false);

	void scroll_to_line(int p_line);
	int get_line_count() const;
	int get_visible_line_count() const;

	VScrollBar *get_v_scroll() { return vscroll; }

	virtual CursorShape get_cursor_shape(const Point2 &p_pos) const;

	void set_selection_enabled(bool p_enabled);
	bool is_selection_enabled() const;
	void selection_copy();

	Error parse_bbcode(const String &p_bbcode);
	Error append_bbcode(const String &p_bbcode);

	void set_use_bbcode(bool p_enable);
	bool is_using_bbcode() const;

	void set_bbcode(const String &p_bbcode);
	String get_bbcode() const;

	void set_text(const String &p_string);

	void set_visible_characters(int p_visible);
	int get_visible_characters() const;
	int get_total_character_count() const;

	void set_percent_visible(float p_percent);
	float get_percent_visible() const;

	RichTextLabel();
	~RichTextLabel();
};

VARIANT_ENUM_CAST(RichTextLabel::Align);
VARIANT_ENUM_CAST(RichTextLabel::ListType);
VARIANT_ENUM_CAST(RichTextLabel::ItemType);

#endif // RICH_TEXT_LABEL_H