add BoxLayout

examples/example.jl

@@ -177,10 +177,12 @@ function start()
 
         compute_time_start = time_ns()
 
+        layout = SW.BoxLayout(SW.BoundingBox(577, 1, 576, 0))
+
         SD.draw!(image, SD.Background(), background_color)
 
         button1 = SW.WidgetID(@__LINE__, @__FILE__)
-        button1_bounding_box = SW.BoundingBox(577, 1, 608, 200)
+        layout, button1_bounding_box = SW.add_widget(layout, SW.VERTICAL, 32, 200)
         button1_value = SW.do_widget!(user_interaction_state, button1, SW.BUTTON, button1_bounding_box, user_input_state.cursor, user_input_state.mouse_left)
         if button1_value
             text_color = 0x00aa0000
@@ -190,7 +192,7 @@ function start()
         SD.draw!(image, SD.TextLine(button1_rectangle.position, "Button 1", font), text_color)
 
         button2 = SW.WidgetID(@__LINE__, @__FILE__)
-        button2_bounding_box = SW.BoundingBox(609, 1, 640, 200)
+        layout, button2_bounding_box = SW.add_widget(layout, SW.VERTICAL, 32, 200)
         button2_value = SW.do_widget!(user_interaction_state, button2, SW.BUTTON, button2_bounding_box, user_input_state.cursor, user_input_state.mouse_left)
         if button2_value
             text_color = 0x00000000
@@ -200,15 +202,15 @@ function start()
         SD.draw!(image, SD.TextLine(button2_rectangle.position, "Button 2", font), text_color)
 
         slider = SW.WidgetID(@__LINE__, @__FILE__)
-        slider_bounding_box = SW.BoundingBox(641, 1, 672, 200)
+        layout, slider_bounding_box = SW.add_widget(layout, SW.VERTICAL, 32, 200)
         slider_value = SW.do_widget!(user_interaction_state, slider, SW.SLIDER, slider_bounding_box, user_input_state.cursor, user_input_state.mouse_left, slider_value)
         slider_rectangle = convert(SD.Rectangle{Int}, slider_bounding_box)
         SD.draw!(image, slider_rectangle, text_color)
         SD.draw!(image, SD.FilledRectangle(slider_rectangle.position, slider_rectangle.height, slider_value), text_color)
         SD.draw!(image, SD.TextLine(slider_rectangle.position, "Slider", font), 0x00ffffff)
 
         text_input = SW.WidgetID(@__LINE__, @__FILE__)
-        text_input_bounding_box = SW.BoundingBox(673, 1, 704, 200)
+        layout, text_input_bounding_box = SW.add_widget(layout, SW.VERTICAL, 32, 200)
         SW.do_widget!(user_interaction_state, text_input, SW.TEXT_INPUT, text_input_bounding_box, user_input_state.cursor, user_input_state.mouse_left, text_line, user_input_state.characters)
         text_input_rectangle = convert(SD.Rectangle{Int}, text_input_bounding_box)
         SD.draw!(image, text_input_rectangle, text_color)

src/SimpleWidgets.jl

@@ -1,6 +1,7 @@
 module SimpleWidgets
 
 include("input.jl")
+include("layout.jl")
 include("utils.jl")
 include("widgets.jl")
 include("ui_state.jl")

src/input.jl

@@ -3,6 +3,11 @@ struct InputButton
     half_transition_count::Int
 end
 
+struct Point
+    i::Int
+    j::Int
+end
+
 struct Cursor
     i::Int
     j::Int
@@ -15,6 +20,8 @@ struct BoundingBox
     j_max::Int
 end
 
+BoundingBox(point::Point, height, width) = BoundingBox(point.i, point.j, point.i + height - one(height), point.j + width - one(width))
+
 press_button(button) = InputButton(true, button.half_transition_count + one(button.half_transition_count))
 release_button(button) = InputButton(false, button.half_transition_count + one(button.half_transition_count))
 reset(button) = InputButton(button.ended_down, zero(button.half_transition_count))

src/layout.jl

@@ -0,0 +1,28 @@
+abstract type AbstractLayout end
+
+struct BoxLayout <: AbstractLayout
+    bounding_box::BoundingBox
+end
+
+abstract type AbstractDirection end
+
+struct Vertical <: AbstractDirection end
+const VERTICAL = Vertical()
+
+struct Horizontal <: AbstractDirection end
+const HORIZONTAL = Horizontal()
+
+update_layout(layout::BoxLayout, ::Vertical, height, width) = BoxLayout(BoundingBox(layout.bounding_box.i_min, layout.bounding_box.j_min, layout.bounding_box.i_max + height, max(layout.bounding_box.j_max, layout.bounding_box.j_min + width - one(width))))
+
+update_layout(layout::BoxLayout, ::Horizontal, height, width) = BoxLayout(BoundingBox(layout.bounding_box.i_min, layout.bounding_box.j_min, max(layout.bounding_box.i_max, layout.bounding_box.i_min + height - one(height)), layout.bounding_box.j_max + width))
+
+get_widget_position(layout::BoxLayout, ::Vertical) = Point(layout.bounding_box.i_max + one(layout.bounding_box.i_max), layout.bounding_box.j_min)
+
+get_widget_position(layout::BoxLayout, ::Horizontal) = Point(layout.bounding_box.i_min, layout.bounding_box.j_max + one(layout.bounding_box.j_max))
+
+function get_widget_bounding_box(layout::BoxLayout, direction::AbstractDirection, height, width)
+    widget_position = get_widget_position(layout, direction)
+    return BoundingBox(widget_position, height, width)
+end
+
+add_widget(layout::BoxLayout, direction::AbstractDirection, height, width) = update_layout(layout, direction, height, width), get_widget_bounding_box(layout, direction, height, width)