natiny.view.set_hook

natiny.view.set_hook(view, hook, fn)

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`	`number`	View handle
`hook`	`integer`	Which event; one of the constants below
`fn`	`function`	Called with the view handle; `nil` removes the hook

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

function(view) end

Argument	Type	Description
`view`	`number`	The view the hook was set on

Nothing the function returns is used. Read what it needs with natiny.view.get_rect, get_hovered, get_pressed and get_pointer.

Example

local button = natiny.view.create(natiny.view.FREE, toolbar)
natiny.view.set_min_size(button, 120, 36)

natiny.view.set_hook(button, natiny.view.HOOK_DRAW, function(self)
    local x, y, w, h = natiny.view.get_rect(self)
    local color = IDLE
    if natiny.view.get_pressed(self) then color = PRESSED
    elseif natiny.view.get_hovered(self) then color = HOVER end
    natiny.render.set_color(color)
    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, "Play",
        natiny.render.ALIGN_CENTER | natiny.render.ALIGN_MIDDLE)
end)

natiny.view.set_hook(button, natiny.view.HOOK_MOUSE_CLICK, function(self)
    start_game()
end)

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.