Extract app preference planning into app core

src/app_core/app_preferences.h

@@ -0,0 +1,114 @@
+#pragma once
+
+#include <cstddef>
+#include <span>
+
+namespace pp::app {
+
+enum class InterfaceDirection {
+    left_to_right,
+    right_to_left,
+};
+
+enum class TimelapseRecordingAction {
+    no_op,
+    start_recording,
+    stop_recording,
+};
+
+struct ScaleApplicationPlan {
+    float scale = 1.0F;
+    float display_density = 1.0F;
+    float font_scale = 1.0F;
+};
+
+struct ScaleOptionSelection {
+    bool has_selection = false;
+    std::size_t index = 0;
+};
+
+struct InterfaceDirectionPlan {
+    InterfaceDirection direction = InterfaceDirection::left_to_right;
+};
+
+struct TimelapsePreferencePlan {
+    bool enabled = true;
+    TimelapseRecordingAction recording_action = TimelapseRecordingAction::no_op;
+};
+
+struct StoredIntegerPreferencePlan {
+    int value = 0;
+};
+
+struct StoredBooleanPreferencePlan {
+    bool value = false;
+};
+
+[[nodiscard]] constexpr ScaleApplicationPlan plan_ui_scale(
+    float requested_scale,
+    float display_density) noexcept
+{
+    return {
+        requested_scale,
+        display_density,
+        requested_scale * display_density,
+    };
+}
+
+[[nodiscard]] constexpr ScaleApplicationPlan plan_viewport_scale(
+    float requested_scale,
+    float display_density = 1.0F) noexcept
+{
+    return {
+        requested_scale,
+        display_density,
+        requested_scale * display_density,
+    };
+}
+
+[[nodiscard]] constexpr ScaleOptionSelection plan_scale_option_selection(
+    float current_scale,
+    std::span<const float> options) noexcept
+{
+    ScaleOptionSelection selection;
+    for (std::size_t index = 0; index < options.size(); ++index) {
+        if (current_scale >= options[index]) {
+            selection.has_selection = true;
+            selection.index = index;
+        }
+    }
+    return selection;
+}
+
+[[nodiscard]] constexpr InterfaceDirectionPlan plan_interface_direction(bool right_to_left) noexcept
+{
+    return {
+        right_to_left ? InterfaceDirection::right_to_left : InterfaceDirection::left_to_right,
+    };
+}
+
+[[nodiscard]] constexpr TimelapsePreferencePlan plan_timelapse_preference(
+    bool enabled,
+    bool recording_running) noexcept
+{
+    if (enabled && !recording_running) {
+        return { enabled, TimelapseRecordingAction::start_recording };
+    }
+    if (!enabled && recording_running) {
+        return { enabled, TimelapseRecordingAction::stop_recording };
+    }
+    return { enabled, TimelapseRecordingAction::no_op };
+}
+
+[[nodiscard]] constexpr StoredBooleanPreferencePlan plan_vr_controllers_preference(
+    bool enabled) noexcept
+{
+    return { enabled };
+}
+
+[[nodiscard]] constexpr StoredIntegerPreferencePlan plan_canvas_cursor_mode(int mode) noexcept
+{
+    return { mode };
+}
+
+}