How to properly setup tweaked themes

[steve725]

Hello, using hello_imgui.ImGuiTweakedTheme() doesn't seem to change the app window background color:

from imgui_bundle import imgui, immapp, hello_imgui, imgui_ctx


class Globals:
    def __init__(self):
        # ---
        self.runner_params = hello_imgui.RunnerParams()
        # ---
        self.addons = immapp.AddOnsParams()
        # ---
        self.val_combo_layout = 0
    
    def setup_runner_params(self):
        self.runner_params = hello_imgui.RunnerParams()
        self.runner_params.app_window_params.window_geometry.size = (1000, 600)
        self.runner_params.callbacks.show_gui = create_gui

    def on_change_layout(self):
        # ---
        tweaked_theme_dark = hello_imgui.ImGuiTweakedTheme()
        tweaked_theme_dark.theme = hello_imgui.ImGuiTheme_.darcula
        tweaked_theme_dark.tweaks.rounding = 8.0
        # ---
        tweaked_theme_light = hello_imgui.ImGuiTweakedTheme()
        tweaked_theme_light.theme = hello_imgui.ImGuiTheme_.light_rounded
        tweaked_theme_light.tweaks.rounding = 8.0

        if self.val_combo_layout == 0:
            hello_imgui.push_tweaked_theme(tweaked_theme_dark)
        elif self.val_combo_layout == 1:
            hello_imgui.push_tweaked_theme(tweaked_theme_light)


gb = Globals()


def create_gui():
    table_main_flags = (
        imgui.TableFlags_.resizable.value | imgui.TableFlags_.borders.value
    )
    # ---
    gb.on_change_layout()
    # ---
    imgui.new_line()
    with imgui_ctx.begin_table("main_frame", 1, table_main_flags) as main_frame:
        if main_frame:
            imgui.table_next_row()
            imgui.table_next_column()
            imgui.new_line()
            # ---
            with imgui_ctx.begin_tab_bar("tab_bar_main") as tab_bar_main:
                if tab_bar_main:
                    with imgui_ctx.begin_tab_item("Tab") as tab_check:
                        if tab_check:
                            imgui.new_line()
                            imgui.new_line()
                            imgui.new_line()
                            # ---
                            imgui.text("Change Layout")
                            # ---
                            imgui.new_line()
                            # ---
                            items = [
                                "Dark",
                                "Light",
                            ]
                            (
                                changed,
                                gb.val_combo_layout,
                            ) = imgui.combo(
                                "##combo_layout",
                                gb.val_combo_layout,
                                items,
                                len(items),
                            )
                            # ---
    hello_imgui.pop_tweaked_theme()

if __name__ == "__main__":
    # ---
    gb.setup_runner_params()
    # ---
    immapp.run(gb.runner_params, gb.addons)

It is possible to change the app window background color at setup with e.g.

self.runner_params.imgui_window_params.background_color = ImVec4( 0.5, 0.5, 0.5, 0.5)

But how can I change the app window background color at runtime using tweaked themes?

[pthom]

Your current code changes the theme at each frame, even if the user did not select a change in the combo box.
I guess this is the origin of your issue.

You can try:

from imgui_bundle import imgui, immapp, hello_imgui, imgui_ctx


class Globals:
    def __init__(self):
        # ---
        self.runner_params = hello_imgui.RunnerParams()
        # ---
        self.addons = immapp.AddOnsParams()
        # ---
        self.val_combo_layout = 0

    def setup_runner_params(self):
        self.runner_params = hello_imgui.RunnerParams()
        self.runner_params.app_window_params.window_geometry.size = (1000, 600)
        self.runner_params.callbacks.show_gui = create_gui

    def on_change_layout(self):
        # ---
        tweaked_theme_dark = hello_imgui.ImGuiTweakedTheme()
        tweaked_theme_dark.theme = hello_imgui.ImGuiTheme_.darcula
        tweaked_theme_dark.tweaks.rounding = 8.0
        # ---
        tweaked_theme_light = hello_imgui.ImGuiTweakedTheme()
        tweaked_theme_light.theme = hello_imgui.ImGuiTheme_.light_rounded
        tweaked_theme_light.tweaks.rounding = 8.0

        if self.val_combo_layout == 0:
            hello_imgui.apply_tweaked_theme(tweaked_theme_dark)  # You could call push_tweaked_theme() instead, but apply_tweaked_theme() is more convenient here
        elif self.val_combo_layout == 1:
            hello_imgui.apply_tweaked_theme(tweaked_theme_light)


gb = Globals()


def create_gui():
    table_main_flags = (
            imgui.TableFlags_.resizable.value | imgui.TableFlags_.borders.value
    )
    # ---
    # gb.on_change_layout()  # Do not call this at each frame! Only call it if the user selected a different theme
    # ---
    imgui.new_line()
    with imgui_ctx.begin_table("main_frame", 1, table_main_flags) as main_frame:
        if main_frame:
            imgui.table_next_row()
            imgui.table_next_column()
            imgui.new_line()
            # ---
            with imgui_ctx.begin_tab_bar("tab_bar_main") as tab_bar_main:
                if tab_bar_main:
                    with imgui_ctx.begin_tab_item("Tab") as tab_check:
                        if tab_check:
                            imgui.new_line()
                            imgui.new_line()
                            imgui.new_line()
                            # ---
                            imgui.text("Change Layout")
                            # ---
                            imgui.new_line()
                            # ---
                            items = [
                                "Dark",
                                "Light",
                            ]
                            (
                                changed,
                                gb.val_combo_layout,
                            ) = imgui.combo(
                                "##combo_layout",
                                gb.val_combo_layout,
                                items,
                                len(items),
                            )

                            # only call on_change_layout if the user selected a different theme
                            if changed:
                                gb.on_change_layout()
                            # ---
    # hello_imgui.pop_tweaked_theme()  # No need to call this here, as we are not calling push_tweaked_theme() at each frame anymore

if __name__ == "__main__":
    # ---
    gb.setup_runner_params()
    # ---
    immapp.run(gb.runner_params, gb.addons)

[steve725]

Thank you very much for the help.