natiny_view_set_hook

void natiny_view_set_hook(NatinyView view, uint32_t hook,
                            natiny_view_fn fn, void* userdata);

Sets the function a view calls when it is drawn, when the pointer does something to it, or when it is destroyed.

A view with a NATINY_VIEW_HOOK_DRAW function draws its children when that function calls natiny_render_view_children. A view without a draw function draws its children automatically.

Parameters

Name	Type	Description
`view`	`NatinyView`	View handle
`hook`	`uint32_t`	Which event; one of the constants below
`fn`	`natiny_view_fn`	Called when the event happens; `NULL` removes the hook
`userdata`	`void*`	Passed to `fn` unchanged; the view does not own it

Constants

Constant	Called
`NATINY_VIEW_HOOK_DRAW`	Every render, to draw the view
`NATINY_VIEW_HOOK_MOUSE_ENTER`	When the pointer comes over the view or one of its pickable descendants
`NATINY_VIEW_HOOK_MOUSE_LEAVE`	When it is no longer over either
`NATINY_VIEW_HOOK_MOUSE_MOVE`	When the pointer moves over the view, or anywhere while the view is pressed
`NATINY_VIEW_HOOK_MOUSE_DOWN`	When the button goes down on the view
`NATINY_VIEW_HOOK_MOUSE_UP`	When the button that pressed the view is released, wherever the pointer is
`NATINY_VIEW_HOOK_MOUSE_CLICK`	After `NATINY_VIEW_HOOK_MOUSE_UP`, when the release is over the view that was pressed
`NATINY_VIEW_HOOK_DESTROY`	When the view is destroyed, before it is gone

Callback

typedef void (*natiny_view_fn)(NatinyView view, void* userdata);

Argument	Type	Description
`view`	`NatinyView`	The view the hook was set on
`userdata`	`void*`	The pointer given with this hook

Example

typedef struct { const char* label; int clicks; } Button;

static void button_draw(NatinyView self, void* userdata) {
    Button* button = userdata;
    float x, y, w, h;
    natiny_view_get_rect(self, &x, &y, &w, &h);
    natiny_render_set_color(natiny_view_get_pressed(self) ? PRESSED
                          : natiny_view_get_hovered(self) ? HOVER : IDLE);
    natiny_render_rounded_rectangle(x, y, w, h, 5, 5, 5, 5);
    natiny_render_set_color(INK);
    natiny_render_text_box(font, x, y, w, h, button->label,
                           NATINY_ALIGN_CENTER | NATINY_ALIGN_MIDDLE);
}

static void button_click(NatinyView self, void* userdata) {
    ((Button*)userdata)->clicks++;
}

static Button play = { "Play", 0 };
NatinyView view = natiny_view_create(NATINY_LAYOUT_FREE);
natiny_view_set_min_size(view, 120, 36);
natiny_view_set_hook(view, NATINY_VIEW_HOOK_DRAW, button_draw, &play);
natiny_view_set_hook(view, NATINY_VIEW_HOOK_MOUSE_CLICK, button_click, &play);

Notes

Every hook except NATINY_VIEW_HOOK_DESTROY runs inside natiny_render_view, after all rectangles are laid out: first the pointer hooks, then NATINY_VIEW_HOOK_DRAW, from the root down.
A scissor a NATINY_VIEW_HOOK_DRAW function begins and does not end is ended when the function returns.
userdata is not freed by the engine. NATINY_VIEW_HOOK_DESTROY is where to free it.