wschod/game/src/ui/widget_core.h

#pragma once

#include <glib-2.0/glib.h>
#include <cglm/cglm.h>

#include "widget_fw.h"
#include "widget_render.h"
#include "widget_layout.h"
#include "widget_style.h"
#include "widget_boilerplate.h"

#include "../util.h"
#include "../resources.h"
#include "../flags.h"
#include "../gl/mesh.h"
#include "../gl/program.h"

#define WFOREACH(widget, child)						\
  for (unsigned int _i = 0; _i < (widget)->children->len; ++_i)		\
    for (Widget *child = g_array_index ((widget)->children, Widget *, _i); child; child = NULL)

#define SCROLL_UP (ivec2) { 0, -1 }
#define SCROLL_DOWN (ivec2) { 0, 1 }

typedef enum WidgetKind
  {
    WIDGET_PLAIN,
    WIDGET_LABEL,
    WIDGET_SCROLLBAR,
    WIDGET_PROGRESS,
    WIDGET_ENTRY,
    
    WIDGET_MULTILINE_TEXT,

    WIDGET_CONTAINER,
    WIDGET_SCROLLABLE,
    WIDGET_FLOWBOX,

    WIDGET_WINDOW
  } WidgetKind;

typedef enum WidgetIcon
  {
    ICON_NONE,
    ICON_CHECKBOX_UNCHECKED,
    ICON_CHECKBOX_CHECKED,
    ICON_MINUS,
    ICON_PLUS,
    ICON_ARROW_LEFT,
    ICON_ARROW_RIGHT,
    ICON_ARROW_UP,
    ICON_ARROW_DOWN
  } WidgetIcon;

typedef enum WidgetEvent
  {
    EVENT_TICK,
    EVENT_LEFT_DOWN,
    EVENT_LEFT_UP,
    EVENT_RIGHT_DOWN,
    EVENT_RIGHT_UP,
    EVENT_MOUSE_ENTER,
    EVENT_MOUSE_LEAVE,
    EVENT_MOUSE_MOVE,
    EVENT_SCROLL_UP,
    EVENT_SCROLL_DOWN,
    EVENT_FOCUS_GAINED,
    EVENT_FOCUS_LOST,
    EVENT_TEXT_INPUT,
    
    EVENT_COUNT
  } WidgetEvent;

typedef enum TextAlignment
  {
    TEXT_ALIGN_LEFT,
    TEXT_ALIGN_CENTER,
    TEXT_ALIGN_RIGHT
  } TextAlignment;

typedef struct LabelWidget
{
  GString *text;
  TextAlignment text_alignment;
} LabelWidget;

typedef struct ScrollbarWidget
{
  struct Widget *target;
  gboolean horizontal;
  /* Used for input. */
  gboolean dragging;
  int drag_offset;
} ScrollbarWidget;

typedef struct ProgressWidget
{
  gboolean horizontal;
  float min, max, *ptr;
} ProgressWidget;

typedef struct EntryWidget
{
  GString *ghost_text;
  GString *content;
  /* cursor_position is in UTF-8 characters. */
  int cursor_position;
} EntryWidget;

typedef struct MultilineTextWidget
{
  GString *text;
  GArray *lines;
  int line_height;
  TextAlignment text_alignment;
} MultilineTextWidget;

typedef struct ContainerWidget
{
  gboolean horizontal;
} ContainerWidget;

typedef struct ScrollableWidget
{
  gboolean layout_horizontal;
  gboolean layout_vertical;
  
  int scroll_amount;
  ivec2 scroll_position;
  ivec2 content_size;
} ScrollableWidget;

typedef struct FlowBoxWidget
{
  gboolean horizontal;
} FlowBoxWidget;

typedef struct WindowWidget
{
  GString *title;
  int titlebar_height;
  gboolean moving, resizing;
  ivec2 drag_offset;
  gboolean resizable_h, resizable_v;
} WindowWidget;

typedef struct Widget
{
  struct Widget *parent;
  GArray *children;

  WidgetKind kind;
  union
  {
    LabelWidget label;
    ScrollbarWidget scrollbar;
    ProgressWidget progress;
    MultilineTextWidget multiline_text;
    EntryWidget entry;

    ContainerWidget container;
    ScrollableWidget scrollable;
    FlowBoxWidget flowbox;

    WindowWidget window;
  };

  gboolean visible;
  gboolean layout_dirty;	/* Unused. */
  gboolean hovered, clicked, focused;
  
  ivec2 position;
  ivec2 size;
  int layout_padding, layout_spacing;
  float layout_weight, aspect_ratio;

  const WidgetStyle *style;
  WidgetIcon icon;

  GString *tooltip;
  
  void (*do_layout) (struct Widget *);
  void (*do_render) (struct Widget *, mat4, int);
  
  void (*on_event[EVENT_COUNT]) (struct Widget *, SDL_Event *sdl_event, void *);
  void *event_data[EVENT_COUNT];

  void (*on_key[SDL_SCANCODE_COUNT]) (struct Widget *, SDL_Event *null, void *);
  void *key_data[SDL_SCANCODE_COUNT];
} Widget;

Widget *Widget_new ();
void Widget_add_child (Widget *parent, Widget *child);

void Widget_entry_input_text (Widget *widget, const char *text);
void Widget_scrollable_scroll (Widget *widget, ivec2 direction);

static inline gboolean wcond_tooltip (Widget *widget, void *userdata) { UNUSED (userdata); return widget->tooltip->len > 0; }
static inline gboolean wcond_event (Widget *widget, void *event) { WidgetEvent e = GPOINTER_TO_INT (event); return widget->on_event[e] != NULL; }
static inline gboolean wcond_any (Widget *widget, void *userdata) { UNUSED (widget, userdata); return TRUE; }

Widget *Widget_find_xy_cond (Widget *widget, ivec2 point, gboolean (*cond_func) (Widget *, void *), void *userdata);

void Widget_tick (Widget *widget);
void Widget_render (Widget *widget, mat4 projection, int window_height);
void Widget_free (Widget *widget);