feat(ui): add interactive custom theme configurator

src/app.cpp

@@ -260,6 +260,24 @@ static void view_settings_read_line(ImGuiContext *, ImGuiSettingsHandler *,
     set_path_setting(view_state->preferences_state.recordings_dir,
                      sizeof(view_state->preferences_state.recordings_dir),
                      line + 14);
+  } else if (strncmp(line, "CustomColor_", 12) == 0) {
+    int idx;
+    float r, g, b, a;
+    if (sscanf(line, "CustomColor_%d=%f,%f,%f,%f", &idx, &r, &g, &b, &a) == 5) {
+      if (idx >= 0 && idx < ImGuiCol_COUNT) {
+        g_custom_colors[idx] = ImVec4(r, g, b, a);
+        g_custom_theme_inited = true;
+      }
+    }
+  } else if (strncmp(line, "CustomAppColor_", 15) == 0) {
+    int idx;
+    float r, g, b, a;
+    if (sscanf(line, "CustomAppColor_%d=%f,%f,%f,%f", &idx, &r, &g, &b, &a) == 5) {
+      if (idx >= 0 && idx < eAppColor_COUNT) {
+        g_custom_app_colors[idx] = ImVec4(r, g, b, a);
+        g_custom_theme_inited = true;
+      }
+    }
   }
 }
 
@@ -303,6 +321,17 @@ static void view_settings_write_all(ImGuiContext * /*ctx*/,
     buf->appendf("RecordingsDir=%s\n",
                  view_state->preferences_state.recordings_dir);
   }
+
+  for (int i = 0; i < ImGuiCol_COUNT; ++i) {
+    buf->appendf("CustomColor_%d=%.2f,%.2f,%.2f,%.2f\n", i,
+                 g_custom_colors[i].x, g_custom_colors[i].y,
+                 g_custom_colors[i].z, g_custom_colors[i].w);
+  }
+  for (int i = 0; i < eAppColor_COUNT; ++i) {
+    buf->appendf("CustomAppColor_%d=%.2f,%.2f,%.2f,%.2f\n", i,
+                 g_custom_app_colors[i].x, g_custom_app_colors[i].y,
+                 g_custom_app_colors[i].z, g_custom_app_colors[i].w);
+  }
   buf->append("\n");
 
   buf->appendf("[%s][ProcessTable]\n", handler->TypeName);

src/style_control.cpp

@@ -160,6 +160,14 @@ void style_control_select_theme(const Theme theme) {
   g_applied_zoom_scale = -1;
 }
 
+void style_control_force_update() {
+  if (g_applied_theme == Theme::COUNT) return;
+  apply_theme(g_applied_theme, &g_base_style);
+  apply_geometry(g_base_style);
+  apply_chart_colormap(g_applied_theme);
+  g_applied_zoom_scale = -1;
+}
+
 void style_control_init(const Theme theme, const float monitor_scale,
                         const int target_fps) {
   register_chart_colormaps();

src/style_control.h

@@ -7,6 +7,7 @@
 void style_control_rebuild(int zoom_pct, int opacity_pct);
 
 void style_control_select_theme(Theme theme);
+void style_control_force_update();
 
 void style_control_init(Theme theme, float monitor_scale, int target_fps);
 

src/themes.h

@@ -21,6 +21,7 @@ enum class Theme : uint8_t {
   Onenord,
   EverforestDark,
   EverforestLight,
+  Custom,
   COUNT
 };
 
@@ -42,6 +43,8 @@ inline const char *theme_name(const Theme theme) {
     return "Everforest Dark";
   case Theme::EverforestLight:
     return "Everforest Light";
+  case Theme::Custom:
+    return "Custom";
   default:
     return "Unknown";
   }
@@ -61,6 +64,10 @@ enum AppColor : uint8_t {
 // opacity - these are foreground highlights, not panel backgrounds.
 inline ImVec4 g_app_colors[eAppColor_COUNT];
 
+inline ImVec4 g_custom_colors[ImGuiCol_COUNT];
+inline ImVec4 g_custom_app_colors[eAppColor_COUNT];
+inline bool g_custom_theme_inited = false;
+
 inline ImU32 app_color_u32(const AppColor idx) {
   return ImGui::ColorConvertFloat4ToU32(g_app_colors[idx]);
 }
@@ -529,6 +536,20 @@ inline void apply_theme(const Theme theme, ImGuiStyle *dst = nullptr) {
     break;
   }
 
+  case Theme::Custom: {
+    if (!g_custom_theme_inited) {
+      ImGui::StyleColorsDark(dst);
+      set_app_colors_dark();
+      for (int i = 0; i < ImGuiCol_COUNT; ++i) g_custom_colors[i] = colors[i];
+      for (int i = 0; i < eAppColor_COUNT; ++i) g_custom_app_colors[i] = g_app_colors[i];
+      g_custom_theme_inited = true;
+    } else {
+      for (int i = 0; i < ImGuiCol_COUNT; ++i) colors[i] = g_custom_colors[i];
+      for (int i = 0; i < eAppColor_COUNT; ++i) g_app_colors[i] = g_custom_app_colors[i];
+    }
+    break;
+  }
+
   default:
     ImGui::StyleColorsLight(dst);
     set_app_colors_light();

src/views/menu_bar.cpp

@@ -25,6 +25,7 @@ static const char *PERIOD_LABELS[] = {"Paused", "0.25s", "0.5s",
 static const char *PREFERENCES_TITLE = "Preferences";
 static const char *ABOUT_TITLE = "About Prock";
 static const char *LICENSES_TITLE = "Third-Party Licenses";
+static const char *THEME_EDITOR_TITLE = "Theme Editor";
 static constexpr float UI_ELEMENT_WIDTH = 220.0f;
 static constexpr float FONT_POPUP_WIDTH = 300.0f;
 static constexpr float SETTING_LABEL_WIDTH = 130.0f;
@@ -149,6 +150,106 @@ static void draw_font_picker(PreferencesState &prefs, const char *label,
   ImGui::PopID();
 }
 
+static void draw_theme_editor_modal(PreferencesState &prefs) {
+  if (prefs.show_theme_editor_modal) {
+    ImGui::OpenPopup(THEME_EDITOR_TITLE);
+  }
+
+  const ImVec2 center = ImGui::GetMainViewport()->GetCenter();
+  ImGui::SetNextWindowPos(center, ImGuiCond_Appearing, ImVec2(0.5f, 0.5f));
+  ImGui::SetNextWindowSize(ImVec2(600.0f * ui_scale(), 500.0f * ui_scale()), ImGuiCond_Appearing);
+
+  if (ImGui::BeginPopupModal(THEME_EDITOR_TITLE, &prefs.show_theme_editor_modal)) {
+    if (popup_close_on_escape()) {
+      prefs.show_theme_editor_modal = false;
+    }
+
+    static ImGuiTextFilter filter;
+
+    ImGui::AlignTextToFramePadding();
+    ImGui::TextUnformatted(ICON_MD_SEARCH);
+    ImGui::SameLine();
+    filter.Draw("##ColorFilter", 200.0f * ui_scale());
+
+    ImGui::SameLine(ImGui::GetWindowContentRegionMax().x - 200.0f * ui_scale());
+    ImGui::SetNextItemWidth(200.0f * ui_scale());
+    if (ImGui::BeginCombo("##LoadPreset", "Load Preset...")) {
+      for (int i = 0; i < static_cast<int>(Theme::Custom); i++) {
+        const Theme t = static_cast<Theme>(i);
+        if (ImGui::Selectable(theme_name(t))) {
+          ImGuiStyle temp_style;
+          apply_theme(t, &temp_style);
+          for (int j = 0; j < ImGuiCol_COUNT; ++j) {
+            g_custom_colors[j] = temp_style.Colors[j];
+          }
+          for (int j = 0; j < eAppColor_COUNT; ++j) {
+            g_custom_app_colors[j] = g_app_colors[j];
+          }
+          style_control_force_update();
+          style_control_rebuild(prefs.zoom_scale_pct, prefs.window_opacity_pct);
+        }
+      }
+      ImGui::EndCombo();
+    }
+
+    ImGui::Spacing();
+
+    if (ImGui::BeginTabBar("ThemeEditorTabs")) {
+      if (ImGui::BeginTabItem("ImGui Colors")) {
+        ImGui::BeginChild("ImGuiColorsScroll", ImVec2(0, -ImGui::GetFrameHeightWithSpacing() - ImGui::GetStyle().ItemSpacing.y));
+        for (int i = 0; i < ImGuiCol_COUNT; ++i) {
+          const char* color_name = ImGui::GetStyleColorName(i);
+          if (!filter.PassFilter(color_name)) continue;
+
+          ImGui::PushID(i);
+          if (ImGui::ColorEdit4(color_name, (float*)&g_custom_colors[i], ImGuiColorEditFlags_AlphaBar | ImGuiColorEditFlags_AlphaPreviewHalf)) {
+            if (prefs.theme == Theme::Custom) {
+              style_control_force_update();
+              style_control_rebuild(prefs.zoom_scale_pct, prefs.window_opacity_pct);
+            }
+          }
+          ImGui::PopID();
+        }
+        ImGui::EndChild();
+        ImGui::EndTabItem();
+      }
+
+      if (ImGui::BeginTabItem("App Colors")) {
+        ImGui::BeginChild("AppColorsScroll", ImVec2(0, -ImGui::GetFrameHeightWithSpacing() - ImGui::GetStyle().ItemSpacing.y));
+        static const char* app_color_names[eAppColor_COUNT] = {
+          "NewProcessRow",
+          "DeadProcessRow",
+          "ErrorText",
+          "WarningText",
+          "InfoText"
+        };
+        for (int i = 0; i < eAppColor_COUNT; ++i) {
+          if (!filter.PassFilter(app_color_names[i])) continue;
+
+          ImGui::PushID(i);
+          if (ImGui::ColorEdit4(app_color_names[i], (float*)&g_custom_app_colors[i], ImGuiColorEditFlags_AlphaBar | ImGuiColorEditFlags_AlphaPreviewHalf)) {
+            if (prefs.theme == Theme::Custom) {
+              style_control_force_update();
+              style_control_rebuild(prefs.zoom_scale_pct, prefs.window_opacity_pct);
+            }
+          }
+          ImGui::PopID();
+        }
+        ImGui::EndChild();
+        ImGui::EndTabItem();
+      }
+      ImGui::EndTabBar();
+    }
+
+    if (ImGui::Button("Close", ImVec2(CLOSE_BUTTON_WIDTH * ui_scale(), 0.0f))) {
+      ImGui::CloseCurrentPopup();
+      prefs.show_theme_editor_modal = false;
+    }
+
+    ImGui::EndPopup();
+  }
+}
+
 static void draw_preferences_modal(PreferencesState &prefs) {
   if (prefs.show_preferences_modal) {
     ImGui::OpenPopup(PREFERENCES_TITLE);
@@ -192,6 +293,14 @@ static void draw_preferences_modal(PreferencesState &prefs) {
       }
       ImGui::EndCombo();
     }
+
+    ImGui::SameLine();
+    if (ImGui::Button("Edit Colors")) {
+      prefs.theme = Theme::Custom;
+      changed_style = true;
+      prefs.show_theme_editor_modal = true;
+      prefs.show_preferences_modal = false;
+    }
 
     changed_style |=
         input_int("Zoom", prefs.zoom_scale_pct, ZOOM_MIN_PCT, ZOOM_MAX_PCT);
@@ -502,6 +611,7 @@ void menu_bar_draw(ViewState &view_state) {
   }
 
   draw_preferences_modal(view_state.preferences_state);
+  draw_theme_editor_modal(view_state.preferences_state);
   draw_about_modal(view_state.preferences_state);
   draw_licenses_modal(view_state.preferences_state);
 }

src/views/menu_bar.h

@@ -18,6 +18,7 @@ struct PreferencesState {
   bool show_preferences_modal = false;
   bool show_about_modal = false;
   bool show_licenses_modal = false;
+  bool show_theme_editor_modal = false;
   bool font_needs_reload = false; // Signal to reload font atlas
   bool show_debug_fps = false;    // Debug-only FPS overlay; flip in code
   bool show_menu_on_alt = false;