Add a dark theme to the VCL GUI runner, with a remembered override

CHANGELOG.md

@@ -27,6 +27,13 @@ versioned baseline.
   before.
 - `gui\src\ASWUnitTests_GUI_Sources.cmake`, which lists the GUI runners' shared units as
   `ASWUNITTESTS_GUI_SOURCES`.
+- A dark theme in the VCL GUI runner, with **View > Theme** to choose it: **Use Windows Setting**
+  (the default) follows Windows' app mode setting, switching as soon as it changes, and **Light**
+  and **Dark** override it. The choice applies without a restart and is saved in the layout file;
+  `--layout-ignore` and `--layout-reset` cover it as they do the layout. Dark is RAD Studio's Carbon
+  VCL style, so a project of your own that runs its tests in the VCL GUI runner needs Carbon among
+  its custom styles (Project > Options > Application > Appearance) for it, and a `WinMain()` that
+  applies the saved theme as `vcl\gui\rad370\ASWUnitTests_VCL_GUI.cpp` does.
 - A `TCLIParser::ParseArguments()` overload that takes the arguments as a
   `std::vector<std::string>`, the program name first, as in `argv`.
 - `UTF8ToWide()` in `ASWUnitTests_Utils.h`, which converts UTF-8 to wide text (UTF-16 on Windows,

Deploy.bat

@@ -77,6 +77,10 @@ call :CopyFile "gui\src\ASWUnitTests_GUI_TestList.cpp" "gui\src\ASWUnitTests_GUI
 if errorlevel 1 exit /b 1
 call :CopyFile "gui\src\ASWUnitTests_GUI_TestList.h" "gui\src\ASWUnitTests_GUI_TestList.h"
 if errorlevel 1 exit /b 1
+call :CopyFile "gui\src\ASWUnitTests_GUI_Theme.cpp" "gui\src\ASWUnitTests_GUI_Theme.cpp"
+if errorlevel 1 exit /b 1
+call :CopyFile "gui\src\ASWUnitTests_GUI_Theme.h" "gui\src\ASWUnitTests_GUI_Theme.h"
+if errorlevel 1 exit /b 1
 call :CopyFile "gui\src\ASWUnitTests_GUI_Tree.cpp" "gui\src\ASWUnitTests_GUI_Tree.cpp"
 if errorlevel 1 exit /b 1
 call :CopyFile "gui\src\ASWUnitTests_GUI_Tree.h" "gui\src\ASWUnitTests_GUI_Tree.h"
@@ -117,6 +121,10 @@ call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_TestList.cpp" "gui\tests\Test_AS
 if errorlevel 1 exit /b 1
 call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_TestList.h" "gui\tests\Test_ASWUnitTests_GUI_TestList.h"
 if errorlevel 1 exit /b 1
+call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_Theme.cpp" "gui\tests\Test_ASWUnitTests_GUI_Theme.cpp"
+if errorlevel 1 exit /b 1
+call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_Theme.h" "gui\tests\Test_ASWUnitTests_GUI_Theme.h"
+if errorlevel 1 exit /b 1
 call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_Tree.cpp" "gui\tests\Test_ASWUnitTests_GUI_Tree.cpp"
 if errorlevel 1 exit /b 1
 call :CopyFile "gui\tests\Test_ASWUnitTests_GUI_Tree.h" "gui\tests\Test_ASWUnitTests_GUI_Tree.h"

README.md

@@ -381,6 +381,15 @@ Reset Layout** restores the default layout right away; `--layout-ignore` and `--
 (below) control this from the command line. Since the file is named after the executable, the two
 GUI runners, and each project's own build of them, keep separate layouts.
 
+In the VCL GUI runner, **View > Theme** chooses a light or dark look. **Use Windows Setting**, the
+default, follows Windows' app mode setting (Settings > Personalization > Colors), and switches as
+soon as it changes, but stays light while high contrast is on, so the window shows high contrast's
+own colors. **Light** and **Dark** keep that look whatever Windows is set to. Dark is RAD Studio's
+Carbon VCL style, and light the standard Windows look. A choice applies right away and is saved in
+the layout file at once, so the next session starts with it; **View > Reset Layout** leaves it as
+it is. The Theme commands are disabled during a run, and a change of the Windows setting during one
+applies when it ends. The Win32 GUI runner always has the standard Windows look, for now.
+
 The window also remembers which tests are checked, in `%APPDATA%\ASWUnitTests\<exe name>.selection`,
 as long as the command line doesn't choose them itself (no `--run`, `--filter`, or partition
 options). What it saves is what Run Selected would run, the checked tests that are shown; the filter
@@ -421,11 +430,12 @@ these differences:
 - `--exit` (GUI-only, requires `--run`) closes the window when that run finishes, and exits with the
   same code the console runner would; a run ended with Stop exits with `1`. Without `--exit`, the
   GUI always exits with `0`.
-- `--layout-ignore` (GUI-only) neither loads nor saves the window layout, so the window opens with
-  the defaults and the saved layout is left as it is.
-- `--layout-reset` (GUI-only) deletes the saved window layout and opens with the defaults, which is
-  a way to recover if a saved layout ever causes a problem. The layout is saved again when the
-  window closes.
+- `--layout-ignore` (GUI-only) neither loads nor saves the window layout, or the VCL GUI runner's
+  theme, so the window opens with the defaults and the saved ones are left as they are. A theme
+  chosen in the View menu then lasts only until the window closes.
+- `--layout-reset` (GUI-only) deletes the saved window layout, and with it the VCL GUI runner's
+  theme, and opens with the defaults, which is a way to recover if a saved layout ever causes a
+  problem. The layout is saved again when the window closes.
 
 A GUI process doesn't make a Windows command prompt wait for it, so a script that needs `--exit`'s
 exit code should start it with `start /wait` (or its own language's equivalent; Bash, including Git
@@ -453,8 +463,10 @@ To run your own tests in it, create a RAD Studio VCL application that defines
 `ASWUNITTESTS_RTL_EXCEPTIONS`, and add to it: the framework's `src` files except `main.cpp`; the
 files in `gui\src` (shared by the GUI runners) and `vcl\gui\src`, including
 `ASWUnitTests_GUI_MainForm.dfm`, with both folders on the include path; your own test modules; and
-a `WinMain()` modeled on `vcl\gui\rad370\ASWUnitTests_VCL_GUI.cpp`, which parses the command line
-and starts the main form.
+a `WinMain()` modeled on `vcl\gui\rad370\ASWUnitTests_VCL_GUI.cpp`, which parses the command line,
+applies the saved theme and starts the main form. For the dark theme, also add RAD Studio's Carbon
+style to the application (Project > Options > Application > Appearance, which this repository's
+project has as `Custom_Styles`); without it, Dark shows the light look.
 
 ### Win32 GUI Runner
 

cmake/CMakeLists.txt

@@ -20,6 +20,7 @@ set(ASWUNITTESTS_SELF_TEST_SOURCES
     ../gui/tests/Test_ASWUnitTests_GUI_Selection.cpp
     ../gui/tests/Test_ASWUnitTests_GUI_Shuffle.cpp
     ../gui/tests/Test_ASWUnitTests_GUI_TestList.cpp
+    ../gui/tests/Test_ASWUnitTests_GUI_Theme.cpp
     ../gui/tests/Test_ASWUnitTests_GUI_Tree.cpp
     ../gui/tests/Test_ASWUnitTests_GUI_View.cpp
     ../tests/Test_ASWTools_Random.cpp

gui/src/ASWUnitTests_GUI_CommandLine.cpp

@@ -45,9 +45,11 @@ std::string TGUICommandLine::GUIOptionsHelp()
         "                      returning the same exit code the console runner would.\n"
         "                      Requires --run.\n"
         "  --layout-ignore     Neither load nor save the window layout (its size,\n"
-        "                      position, and panel sizes); open with the defaults.\n"
-        "  --layout-reset      Delete the saved window layout and open with the\n"
-        "                      defaults; the layout is saved again on closing.\n"
+        "                      position, and panel sizes) or the VCL GUI's theme;\n"
+        "                      open with the defaults.\n"
+        "  --layout-reset      Delete the saved window layout (and the VCL GUI's\n"
+        "                      theme) and open with the defaults; the layout is saved\n"
+        "                      again on closing.\n"
         "\n"
         "Ignored by the GUI: --list, --pause, and the color options.\n";
 }

gui/src/ASWUnitTests_GUI_Commands.cpp

@@ -55,6 +55,7 @@ TGUICommandStates GUICommandStates(TGUICommandContext const& context)
     states.ShuffleOrder = idle;
     states.ShuffleSeed = idle;
     states.Stop = context.Running;
+    states.Theme = idle;
 
     return states;
 }

gui/src/ASWUnitTests_GUI_Commands.h

@@ -58,7 +58,9 @@ struct TGUICommandContext
 //
 // Whether each of a GUI runner's commands is enabled, one member per
 // command, named as in the VCL GUI runner's actions (e.g. RunSelected for
-// Act_RunSelected), plus the filter box.
+// Act_RunSelected), plus the filter box. Theme is the VCL GUI runner's
+// View > Theme menu, its three actions together; the Win32 GUI runner has no
+// themes yet, so it has no command that uses it.
 /////////////////////////////////////////////////////////////////////////////
 struct TGUICommandStates
 {
@@ -80,6 +82,7 @@ struct TGUICommandStates
     bool ShuffleOrder = false;
     bool ShuffleSeed = false;
     bool Stop = false;
+    bool Theme = false;
 };
 
 //---------------------------------------------------------------------------
@@ -90,7 +93,8 @@ struct TGUICommandStates
 //   Details, Expand All, Collapse All, and Reset Layout) are enabled. Tests run on the GUI's main thread, so a
 //   modal dialog (About, Command Line Options, Shuffle Seed, Export JUnit Report) would hold up the run until
 //   it closed; the run's tests and order are already decided, so checking tests and changing the shuffle
-//   would only mislead; and changing the filter would rebuild the tree the run is updating.
+//   would only mislead; changing the filter would rebuild the tree the run is updating; and changing the theme
+//   would recreate the windows the run is updating.
 // - Run Selected and Run Failed stay disabled once a run has been aborted.
 // - Run Failed and Select Failed need a failed test, Export JUnit Report a finished run's report, Copy Details a
 //   selected node, and Expand All and Collapse All a tree with nodes.

gui/src/ASWUnitTests_GUI_Sources.cmake

@@ -19,6 +19,7 @@ set(ASWUNITTESTS_GUI_SOURCES
     "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_Selection.cpp"
     "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_Shuffle.cpp"
     "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_TestList.cpp"
+    "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_Theme.cpp"
     "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_Tree.cpp"
     "${ASWUNITTESTS_GUI_SOURCE_DIR}/ASWUnitTests_GUI_View.cpp"
 )

gui/src/ASWUnitTests_GUI_Theme.cpp

@@ -0,0 +1,117 @@
+/* **************************************************************************
+ASWUnitTests_GUI_Theme.cpp
+Author: Anthony S. West - ASW Software
+
+See header for info.
+
+Copyright 2026 ASW Software
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+************************************************************************** */
+
+//---------------------------------------------------------------------------
+// Module header
+#include "ASWUnitTests_GUI_Theme.h"
+//---------------------------------------------------------------------------
+#include <algorithm>
+#include <optional>
+#include <string>
+//---------------------------------------------------------------------------
+
+namespace
+{
+
+char const ThemeKey[] = "Theme";
+char const ViewSection[] = "View";
+
+//---------------------------------------------------------------------------
+
+bool SameText(std::string const& a, std::string const& b);
+char ToLowerASCII(char c);
+
+//---------------------------------------------------------------------------
+/*
+    SameText
+
+    Whether 'a' and 'b' are the same, ignoring ASCII case, as the INI document matches section and key names.
+*/
+bool SameText(std::string const& a, std::string const& b)
+{
+    return a.size() == b.size() && std::equal(a.begin(), a.end(), b.begin(), [](char x, char y)
+        {
+            return ToLowerASCII(x) == ToLowerASCII(y);
+        });
+}
+//---------------------------------------------------------------------------
+char ToLowerASCII(char c)
+{
+    return (c >= 'A' && c <= 'Z') ? static_cast<char>(c - 'A' + 'a') : c;
+}
+//---------------------------------------------------------------------------
+
+} // namespace
+
+//---------------------------------------------------------------------------
+
+namespace ASWUnitTests
+{
+
+//---------------------------------------------------------------------------
+bool GUIThemeIsDark(EGUITheme theme, bool windowsAppsUseDark, bool highContrast)
+{
+    switch (theme)
+    {
+        case EGUITheme::Dark:
+            return true;
+
+        case EGUITheme::Light:
+            return false;
+
+        case EGUITheme::Windows:
+            break;
+    }
+
+    return windowsAppsUseDark && !highContrast;
+}
+//---------------------------------------------------------------------------
+EGUITheme LoadGUITheme(TGUIINIDocument const& ini)
+{
+    std::optional<std::string> const name = ini.ReadString(ViewSection, ThemeKey);
+
+    if (name.has_value())
+    {
+        if (SameText(*name, "Dark"))
+            return EGUITheme::Dark;
+
+        if (SameText(*name, "Light"))
+            return EGUITheme::Light;
+    }
+
+    return EGUITheme::Windows;
+}
+//---------------------------------------------------------------------------
+void SaveGUITheme(TGUIINIDocument& ini, EGUITheme theme)
+{
+    char const* name = "Windows";
+
+    if (theme == EGUITheme::Dark)
+        name = "Dark";
+    else if (theme == EGUITheme::Light)
+        name = "Light";
+
+    ini.WriteString(ViewSection, ThemeKey, name);
+}
+//---------------------------------------------------------------------------
+
+} // namespace ASWUnitTests

gui/src/ASWUnitTests_GUI_Theme.h

@@ -0,0 +1,62 @@
+/* **************************************************************************
+ASWUnitTests_GUI_Theme.h
+Author: Anthony S. West - ASW Software
+
+Copyright 2026 ASW Software
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+************************************************************************** */
+
+//---------------------------------------------------------------------------
+#ifndef ASWUnitTests_GUI_ThemeH
+#define ASWUnitTests_GUI_ThemeH
+//---------------------------------------------------------------------------
+#include "ASWUnitTests_GUI_INIDocument.h"
+//---------------------------------------------------------------------------
+
+namespace ASWUnitTests
+{
+
+/////////////////////////////////////////////////////////////////////////////
+// EGUITheme
+//
+// A GUI runner's theme, as chosen in the VCL GUI runner's View > Theme menu
+// and saved in its layout file. Contains no UI code, so it's unit tested
+// from the console runners (see gui/tests/Test_ASWUnitTests_GUI_Theme.cpp).
+// The Win32 GUI runner has no themes yet.
+/////////////////////////////////////////////////////////////////////////////
+enum class EGUITheme
+{
+    Windows, // Follows Windows' setting for apps, light or dark; the default.
+    Light,
+    Dark
+};
+
+//---------------------------------------------------------------------------
+
+// Whether 'theme' is dark: Light and Dark as chosen, and Windows as 'windowsAppsUseDark' (Windows' app mode
+// setting) says, except that it's light while 'highContrast' is on, so the window shows high contrast's own
+// colors.
+bool GUIThemeIsDark(EGUITheme theme, bool windowsAppsUseDark, bool highContrast);
+// Reads the theme SaveGUITheme() wrote to 'ini', its [View] section's Theme key, ignoring (ASCII) case.
+// Windows when it's missing or isn't a theme's name.
+EGUITheme LoadGUITheme(TGUIINIDocument const& ini);
+// Writes 'theme' to 'ini', as "Windows", "Light" or "Dark". The file itself is written from the document's
+// Text() afterward.
+void SaveGUITheme(TGUIINIDocument& ini, EGUITheme theme);
+
+} // namespace ASWUnitTests
+
+//---------------------------------------------------------------------------
+#endif // #ifndef ASWUnitTests_GUI_ThemeH

gui/tests/Test_ASWUnitTests_GUI_Commands.cpp

@@ -75,6 +75,7 @@ std::string EnabledCommands(TGUICommandStates const& states)
     add(states.ShuffleOrder, "ShuffleOrder");
     add(states.ShuffleSeed, "ShuffleSeed");
     add(states.Stop, "Stop");
+    add(states.Theme, "Theme");
 
     return text;
 }
@@ -141,7 +142,7 @@ void TTest_ASWUnitTests_GUI_Commands::Test_GUICommandStates_AbortedRunCannotRunA
 
     // Act and Assert
     CheckEquals(std::string("About CommandLineOptions Exit ExportJUnitReport FilterBox FocusFilter ResetLayout "
-        "SelectAll SelectFailed SelectNone ShuffleOrder ShuffleSeed"), EnabledCommands(GUICommandStates(context)),
+        "SelectAll SelectFailed SelectNone ShuffleOrder ShuffleSeed Theme"), EnabledCommands(GUICommandStates(context)),
         __func__, __LINE__, "neither Run Selected nor Run Failed, but everything else that doesn't run tests");
 }
 //---------------------------------------------------------------------------
@@ -153,15 +154,15 @@ void TTest_ASWUnitTests_GUI_Commands::Test_GUICommandStates_FailuresEnableRunAnd
 
     // Act and Assert
     CheckEquals(std::string("About CommandLineOptions Exit FilterBox FocusFilter ResetLayout RunFailed RunSelected "
-        "SelectAll SelectFailed SelectNone ShuffleOrder ShuffleSeed"), EnabledCommands(GUICommandStates(context)),
+        "SelectAll SelectFailed SelectNone ShuffleOrder ShuffleSeed Theme"), EnabledCommands(GUICommandStates(context)),
         __func__, __LINE__, "Run Failed and Select Failed, once a test has failed");
 }
 //---------------------------------------------------------------------------
 void TTest_ASWUnitTests_GUI_Commands::Test_GUICommandStates_IdleWithNothingRunYet()
 {
     // Act and Assert: as the window opens, before its tree is built.
     CheckEquals(std::string("About CommandLineOptions Exit FilterBox FocusFilter ResetLayout RunSelected SelectAll "
-        "SelectNone ShuffleOrder ShuffleSeed"), EnabledCommands(GUICommandStates(TGUICommandContext())), __func__,
+        "SelectNone ShuffleOrder ShuffleSeed Theme"), EnabledCommands(GUICommandStates(TGUICommandContext())), __func__,
         __LINE__, "nothing that needs a failure, a report, a selection, or tree nodes, and not Stop");
 }
 //---------------------------------------------------------------------------