Dropdown box

program.odin

@@ -20,12 +20,28 @@ FontStyle :: struct {
 	size, spacing: f32
 }
 
+ProgramState :: enum {
+	Normal,
+	Message,
+}
+
+ProgramMessageType :: enum {
+	ChangeMatrixTypeClearData,
+}
+
+@rodata program_messages := [ProgramMessageType]cstring {
+	.ChangeMatrixTypeClearData = "Changing the matrix type will delete all current matrices.\nAre you sure you want to do this?",
+}
+
 Program :: struct {
-	ui_state: UiState,
+	ui_state: UiContext,
 	matrix_field_pool: FieldPool(f32),
-	matrix_mode: MatrixType,
+	matrix_mode_perceived: MatrixType,
+	matrix_mode_actual: MatrixType,
 	grid: Grid,
 	font_style: FontStyle,
+	state: ProgramState,
+	message_type: ProgramMessageType,
 }
 
 Grid :: struct {
@@ -45,6 +61,11 @@ field_pool_get :: proc(pool: ^FieldPool($T), count: int) -> (values: []T, inputs
 	return fixed_pool.get(&pool.values, count), fixed_pool.get(&pool.inputs, count)
 }
 
+field_pool_clear :: proc(pool: ^FieldPool($T)) {
+	fixed_pool.clear(&pool.values)
+	fixed_pool.clear(&pool.inputs)
+}
+
 field_pool_init :: proc(pool: ^FieldPool($T), capacity: int, allocator := context.allocator) {
 	fixed_pool.init(&pool.values, capacity, allocator)
 	fixed_pool.init(&pool.inputs, capacity, allocator)
@@ -193,7 +214,17 @@ init :: proc() {
 	ui_init(&program.ui_state, ui_style, {0, 0}, context.temp_allocator)
 }
 
-update :: proc() {
+program_set_message_state :: proc(program: ^Program, message: ProgramMessageType) {
+	program.state = .Message
+	program.message_type = message
+}
+
+program_matrix_mode_dropdown_callback :: proc(previous, current: i32, data: rawptr) {
+	program := cast(^Program)data
+	program_set_message_state(program, .ChangeMatrixTypeClearData)
+}
+
+program_build_ui :: proc() -> []UiElement {
 	matrix_add_button_callback_data := UiButton_AddMat2CallbackData {
 		program = &program,
 		mat = mat2{0, 1, 2, 3},
@@ -210,8 +241,12 @@ update :: proc() {
 			ui_button(ui_button_size_top_bar, {label = "#12#"})
 			ui_same_line()
 			matrix_options := enum_to_raygui_options_string(MatrixType, context.temp_allocator)
-			matrix_mode_ref := cast(^i32)&program.matrix_mode
-			ui_dropdown(ui_dropdown_size_top_bar, {label = matrix_options, active = matrix_mode_ref})
+			matrix_mode_ref := cast(^i32)&program.matrix_mode_perceived
+			ui_dropdown(ui_dropdown_size_top_bar, {
+				label = matrix_options,
+				active = matrix_mode_ref,
+				callback = program_matrix_mode_dropdown_callback,
+				callback_data = cast(rawptr)&program})
 		ui_container_end()
 		ui_container_begin({label = "Matrices"})
 		field_pool := &program.matrix_field_pool
@@ -227,12 +262,10 @@ update :: proc() {
 			}
 		}
 		ui_container_end()
-	ui_elements := ui_end()
-
-	rl.BeginDrawing()
-	defer rl.EndDrawing()
-	rl.ClearBackground(rl.BLACK)
+	return ui_end()
+}
 
+program_render_ui :: proc(ui_elements: []UiElement) {
 	for element in ui_elements {
 		switch element.type {
 		case .Button:
@@ -259,17 +292,59 @@ update :: proc() {
 			style := program.ui_state.style
 			draw_text(data.text, rect_get_tl(element.area), style.font_style, data.color)
 		case .DropDown:
-			data := element.data.(UiElementData_DropDown)
+			data := element.data.(UiElementData_Dropdown)
 			edit_mode := ui_element_is_editing(program.ui_state, element.id)
+			active_previous := data.active^
 			if rl.GuiDropdownBox(element.area, data.label, data.active, edit_mode) {
 				if edit_mode {
 					ui_element_focus_reset(&program.ui_state)
+					if active_previous != data.active^ && data.callback != nil {
+						data.callback(active_previous, data.active^, data.callback_data)
+					}
 				} else {
 					ui_element_focus(&program.ui_state, element.id)
 				}
 			}
 		}
 	}
+}
+
+update :: proc() {
+	ui_elements := program_build_ui()
+
+	rl.BeginDrawing()
+	defer rl.EndDrawing()
+	rl.ClearBackground(rl.BLACK)
+
+	if program.state != .Normal {
+		rl.GuiDisable()
+	}
+	program_render_ui(ui_elements)
+	if program.state != .Normal {
+		rl.GuiEnable()
+	}
+
+	switch program.state {
+	case .Normal:
+	case .Message:
+		switch program.message_type {
+		case .ChangeMatrixTypeClearData:
+			size := v2{224.0, 128.0}
+			position := v2(iv2{rl.GetRenderWidth(), rl.GetRenderHeight()} / 2.0) - size / 2.0
+			area := rect2{**position, **size}
+			action := rl.GuiMessageBox(area, "Message", program_messages[program.message_type], "Confirm;Cancel")
+			switch action {
+			case 0:
+			case 1:
+				field_pool_clear(&program.matrix_field_pool)
+				program.matrix_mode_actual = program.matrix_mode_perceived
+				program.state = .Normal
+			case 2:
+				program.matrix_mode_perceived = program.matrix_mode_actual
+				program.state = .Normal
+			}
+		}
+	}
 
 	free_all(context.temp_allocator)
 }