enum SLIDER_UPDATE {
	realtime,
	release,
	none,
}

function slider(_min, _max, _step, _onModify = noone, _onRelease = noone) : widget() constructor {
	minn = _min; curr_minn = _min;
	maxx = _max; curr_maxx = _max;
	stepSize = _step;
	
	current_value = 0;
	slide_speed   = 1 / 10;
	
	side_button = noone;
	onModify    = _onModify;
	onRelease   = _onRelease;
	onApply     = function(val) {
		if(onModify)  onModify(val);
		if(onRelease) onRelease();
	}
	
	update_stat = SLIDER_UPDATE.realtime;
	
	spr		 = THEME.slider;
	blend    = c_white;
	dragging = noone;
	drag_sv  = 0;
	handle_w = ui(20);
	
	tb_value = new textBox(TEXTBOX_INPUT.number, onApply);
	font     = noone;
	
	static modifyValue = function(value) { #region
		value = clamp(value, curr_minn, curr_maxx);
		onModify(value);
	} #endregion
	
	static setSlideSpeed = function(speed) { #region
		tb_value.setSlidable(speed);
	} #endregion
	
	static setInteract = function(interactable = noone) { #region
		self.interactable     = interactable;
		tb_value.interactable = interactable;
	} #endregion
	
	static register = function(parent = noone) { #region
		tb_value.register(parent);
	} #endregion
	
	static drawParam = function(params) { #region
		return draw(params.x, params.y, params.w, params.h, params.data, params.m);
	} #endregion
	
	static draw = function(_x, _y, _w, _h, _data, _m, tb_w = 64, halign = fa_left, valign = fa_top) { #region
		x = _x;
		y = _y;
		w = _w;
		h = _h;
		if(!is_real(_data)) return;
		
		if(!dragging) current_value = _data;
		
		if(side_button) {
			side_button.setFocusHover(active, hover);
			side_button.draw(_x + _w - ui(32), _y + _h / 2 - ui(32 / 2), ui(32), ui(32), _m, THEME.button_hide);
			_w -= ui(40);
		}
		
		switch(halign) { #region
			case fa_left:   _x = _x;			break;	
			case fa_center: _x = _x - _w / 2;	break;	
			case fa_right:  _x = _x - _w;		break;	
		} #endregion
		
		switch(valign) { #region
			case fa_top:    _y = _y;			break;	
			case fa_center: _y = _y - _h / 2;	break;	
			case fa_bottom: _y = _y - _h;		break;	
		} #endregion
		
		var _rang = abs(maxx - minn);
		if(!dragging) {
			curr_minn = (current_value >= minn)? minn : minn - ceil(abs(current_value - minn) / _rang) * _rang; 
			curr_maxx = (current_value <= maxx)? maxx : maxx + ceil(abs(current_value - maxx) / _rang) * _rang;
		}
		
		var sw = _w;
		
		if(tb_w > 0) {
			sw = _w - (tb_w + ui(16));
			
			tb_value.font = font;
			tb_value.setFocusHover(active, hover);
			tb_value.draw(_x + sw + ui(16), _y, tb_w, _h, current_value, _m);
			tb_value.setRange(curr_minn, curr_maxx);
		}
		
		draw_sprite_stretched_ext(spr, 0, _x - ui(4), _y + _h / 2 - ui(4), sw + ui(8), ui(8), blend, 1);
			
		if(stepSize >= 1 && sw / ((curr_maxx - curr_minn) / stepSize) > ui(16)) {
			for( var i = curr_minn; i <= curr_maxx; i += stepSize ) {
				var _v  = round(i / stepSize) * stepSize;
				var _cx = _x + clamp((_v - curr_minn) / (curr_maxx - curr_minn), 0, 1) * sw;
				draw_sprite_stretched_ext(spr, 4, _cx - ui(4), _y + _h / 2 - ui(4), ui(8), ui(8), COLORS.widget_slider_step, 1);	
			}
		}
		
		var _pg = clamp((current_value - curr_minn) / (curr_maxx - curr_minn), 0, 1) * sw;
		var _kx = _x + _pg;
		draw_sprite_stretched_ext(spr, 1, _kx - handle_w / 2, _y, handle_w, _h, blend, interactable * 0.75 + 0.25);
		
		if(dragging) {
			draw_sprite_stretched_ext(spr, 3, _kx - handle_w / 2, _y, handle_w, _h, COLORS._main_accent, 1);
			
			var val = (dragging.drag_sx - dragging.drag_msx) / dragging.drag_sw * (curr_maxx - curr_minn) + curr_minn;
			val = round(val / stepSize) * stepSize;
			val = clamp(val, curr_minn, curr_maxx);
			
			if(key_mod_press(CTRL))
				val = round(val);
			
			current_value = val;
			if(update_stat == SLIDER_UPDATE.realtime && onModify != noone && onModify(val)) 
				UNDO_HOLDING = true;
			
			MOUSE_BLOCK = true;
			
			if(mouse_check_button_pressed(mb_right)) {
				onModify(drag_sv);
				instance_destroy(dragging);
				dragging     = noone;
				UNDO_HOLDING = false;
				
			} else if(mouse_release(mb_left)) {
				if(update_stat == SLIDER_UPDATE.release && onModify != noone) 
					onModify(val);
				
				instance_destroy(dragging);
				dragging = noone;
				if(onRelease != noone) onRelease(val);
				UNDO_HOLDING = false;
			}
		} else {
			if(hover && (point_in_rectangle(_m[0], _m[1], _x, _y, _x + sw, _y + _h) || point_in_rectangle(_m[0], _m[1], _kx - handle_w / 2, _y, _kx + handle_w / 2, _y + _h))) {
				draw_sprite_stretched_ext(spr, 2, _kx - handle_w / 2, _y, handle_w, _h, blend, 1);
				
				if(mouse_press(mb_left, active)) {
					dragging = instance_create(0, 0, slider_Slider);
					dragging.drag_sx   = _m[0];
					dragging.drag_msx  = _x;
					dragging.drag_sw   = sw;
					
					drag_sv = current_value;
				}
				
				var amo = slide_speed;
				if(key_mod_press(CTRL)) amo *= 10;
				if(key_mod_press(ALT))  amo /= 10;
				
				if(key_mod_press(SHIFT) && mouse_wheel_down())	modifyValue(_data + amo * SCROLL_SPEED);
				if(key_mod_press(SHIFT) && mouse_wheel_up())	modifyValue(_data - amo * SCROLL_SPEED);
			}
		}
		
		resetFocus();
		
		return h;
	} #endregion
}