[wip] Windows: system theme

linux/java/org/jetbrains/jwm/WindowX11.java

@@ -33,6 +33,27 @@ public void unmarkText() {
         assert _onUIThread();
         // TODO: impl me!
     }
+    @Override
+    public Theme setTheme(Theme theme) {
+        // TODO: Impl me!
+        return theme;
+    }
+
+    @Override
+    public AppearancePreference getAppearancePreference() {
+        throw new UnsupportedOperationException();
+    }
+
+
+    @Override
+    public Theme getCurrentTheme(){
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isHighContrast(){
+        throw new UnsupportedOperationException();
+    }
 
     @Override 
     public UIRect getWindowRect() {
@@ -145,4 +166,4 @@ public Window restore() {
     @ApiStatus.Internal public native void _nMinimize();
     @ApiStatus.Internal public native void _nRestore();
     @ApiStatus.Internal public native Screen _nSetTitle(byte[] title);
-}
+}

macos/java/org/jetbrains/jwm/WindowMac.java

@@ -23,7 +23,28 @@ public void unmarkText() {
         assert _onUIThread();
         // TODO: impl me!
     }
+
+    @Override
+    public Theme setTheme(Theme theme) {
+        // TODO: Impl me!
+        return theme;
+    }
+
+    @Override
+    public AppearancePreference getAppearancePreference() {
+        throw new UnsupportedOperationException();
+    }
 
+    @Override
+    public Theme getCurrentTheme(){
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isHighContrast(){
+        throw new UnsupportedOperationException();
+    }
+
     @Override 
     public UIRect getWindowRect() {
         assert _onUIThread();
@@ -146,4 +167,4 @@ public void close() {
     @ApiStatus.Internal public native void _nMaximize();
     @ApiStatus.Internal public native void _nRestore();
     @ApiStatus.Internal public native void _nClose();
-}
+}

shared/cc/ThemeHelper.hh

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace jwm {
+    // must be kept in sync with Theme.java
+    enum class Theme { System, Light, Dark };
+
+    class ThemeHelper {
+       public:
+           Theme getCurrentTheme();
+           Theme setTheme(Theme theme);
+           bool isHighContrast();
+    };
+}  // namespace jwm

shared/java/org/jetbrains/jwm/AppearancePreference.java

@@ -0,0 +1,10 @@
+package org.jetbrains.jwm;
+
+import lombok.*;
+
+
+@Data
+public class AppearancePreference {
+    private final Theme _theme;
+    private final boolean _isHighConstast;
+} 

shared/java/org/jetbrains/jwm/Theme.java

@@ -0,0 +1,18 @@
+package org.jetbrains.jwm;
+
+import org.jetbrains.annotations.*;
+
+
+
+// must be kept in sync with ThemeHelper.hh
+public enum Theme {
+    SYSTEM,
+    LIGHT,
+    DARK;
+
+    @ApiStatus.Internal public static final Theme[] _values = values();
+
+    public static Theme makeFromInt(int v) {
+        return _values[v];
+    }
+}

shared/java/org/jetbrains/jwm/Window.java

@@ -101,6 +101,33 @@ public Window setTextInputClient(@Nullable TextInputClient client) {
      */
     public abstract UIRect getContentRect();
 
+
+    /**
+     * try to set theme. 
+     * If theme is successfully updated, this method returns updated theme.
+     *
+     * @return        updated theme/current theme   
+     */
+    public abstract Theme setTheme(Theme theme);
+
+
+    /**
+     * get AppearancePreference.
+     */
+     public abstract AppearancePreference getAppearancePreference();
+
+    /**
+     * get current OS theme.
+     * 
+     * In Windows, if dark mode is not supported, this method always returns Theme.LIGHT.
+     */ 
+    public abstract Theme getCurrentTheme();
+
+    /**
+     * get if OS currently uses high contrast mode
+     */
+    public abstract boolean isHighContrast();
+
     /**
      * <p>Get window content position and size on the screen as UI rect.</p>
      * <p>This function has the same effect as {@link #getContentRect()}, but returned rect has screen relative coordinates.</p>
@@ -297,4 +324,4 @@ public void close() {
     @ApiStatus.Internal public native void _nSetEventListener(Consumer<Event> eventListener);
     @ApiStatus.Internal public native void _nSetTextInputClient(TextInputClient client);
     @ApiStatus.Internal public abstract void _nSetMouseCursor(int cursorIdx);
-}
+}

windows/CMakeLists.txt

@@ -45,6 +45,10 @@ set(JWM_WINDOWS_SOURCES_CXX
     cc/LayerRaster.hh
     cc/LayerWGL.cc
     cc/LayerWGL.hh
+    cc/ThemeHelperWin32.cc
+    cc/ThemeHelperWin32.hh
+    cc/SystemWin32.cc
+    cc/SystemWin32.hh
     cc/PlatformWin32.hh
     cc/ScreenWin32.cc
     cc/ScreenWin32.hh
@@ -80,6 +84,7 @@ target_link_libraries(jwm PRIVATE "shcore")
 target_link_libraries(jwm PRIVATE "gdi32")
 target_link_libraries(jwm PRIVATE "opengl32")
 target_link_libraries(jwm PRIVATE "user32")
+target_link_libraries(jwm PRIVATE "uxtheme")
 target_link_libraries(jwm PRIVATE "Dxva2")
 target_link_libraries(jwm PRIVATE "d3d12")
 target_link_libraries(jwm PRIVATE "dxgi")

windows/cc/SystemWin32.cc

@@ -0,0 +1,39 @@
+#include "SystemWin32.hh"
+
+#include <VersionHelpers.h>
+#include <WinUser.h>
+#include <stdio.h>
+
+#include <Log.hh>
+#include <PlatformWin32.hh>
+
+OSVERSIONINFOW jwm::SystemWin32::getOSVersion() {
+    HMODULE hMod;
+    jwm::SystemWin32::FnRtlGetVersion fn;
+    hMod = LoadLibrary(TEXT("ntdll.dll"));
+    if (!hMod) {
+        JWM_VERBOSE("ntdll.dll not found");
+        throw "LibNotFound";
+    }
+    fn = (jwm::SystemWin32::FnRtlGetVersion)GetProcAddress(hMod, "RtlGetVersion");
+    if (fn == 0) {
+        JWM_VERBOSE("Failed to load RtlGetVersion function from ntdll.dll");
+        FreeLibrary(hMod);
+        throw "FunctionNotFound";
+    }
+    NTSTATUS status;
+    OSVERSIONINFOW _osVersionInfo;
+    OSVERSIONINFOW *_osVersionInfoPtr = &_osVersionInfo;
+    ZeroMemory(_osVersionInfoPtr, sizeof(*_osVersionInfoPtr));
+    _osVersionInfoPtr->dwOSVersionInfoSize = sizeof(*_osVersionInfoPtr);
+    status = fn(&_osVersionInfo);
+    FreeLibrary(hMod);
+    if (status != 0) {
+        JWM_VERBOSE("Failed to get osVersionInfo");
+        throw "FailedToGetOSVersionInfo";
+    }
+    JWM_VERBOSE("get os version: '" << _osVersionInfo.dwMajorVersion << "."
+                                    << _osVersionInfo.dwMinorVersion << "-"
+                                    << _osVersionInfo.dwBuildNumber << "'");
+    return _osVersionInfo;
+}

windows/cc/SystemWin32.hh

@@ -0,0 +1,11 @@
+#pragma once
+#include <PlatformWin32.hh>
+
+#include "ThemeHelper.hh"
+#include "ThemeHelperWin32.hh"
+namespace jwm {
+    namespace SystemWin32 {
+        typedef NTSTATUS(WINAPI *FnRtlGetVersion)(OSVERSIONINFOW *);
+        OSVERSIONINFOW getOSVersion();
+    }  // namespace SystemWin32
+}  // namespace jwm

windows/cc/ThemeHelperWin32.cc

@@ -0,0 +1,119 @@
+#include "ThemeHelperWin32.hh"
+
+#include <Uxtheme.h>
+#include <VersionHelpers.h>
+#include <WinUser.h>
+#include <stdio.h>
+#include <Log.hh>
+#include <PlatformWin32.hh>
+#include "SystemWin32.hh"
+#include "ThemeHelper.hh"
+
+jwm::Theme jwm::ThemeHelperWin32::getCurrentTheme() {
+    if (!_isDarkModeSupported()) {
+        JWM_VERBOSE("Dark mode is not supported.");
+        return jwm::Theme::Light;
+    }
+    HMODULE hUxTheme = LoadLibrary(TEXT("uxtheme.dll"));
+    if (!hUxTheme) {
+        JWM_VERBOSE("uxtheme.dll not found.");
+        return jwm::Theme::Light;
+    }
+    jwm::FnShouldAppsUseDarkMode hFunc;
+    hFunc =
+        (FnShouldAppsUseDarkMode)GetProcAddress(hUxTheme, MAKEINTRESOURCEA(132));
+    if (hFunc == nullptr) {
+        JWM_VERBOSE("shouldAppsUseDarkMode not found.");
+        FreeLibrary(hUxTheme);
+        return jwm::Theme::Light;
+    }
+    bool shouldAppsUseDarkMode;
+    shouldAppsUseDarkMode = hFunc();
+    FreeLibrary(hUxTheme);
+    return shouldAppsUseDarkMode ? jwm::Theme::Dark : jwm::Theme::Light;
+}
+
+jwm::Theme jwm::ThemeHelperWin32::setTheme(jwm::Theme theme) {
+    bool isDarkMode =
+        (theme == jwm::Theme::Dark) ? _isDarkModeSupported() : false;
+
+    LPCWSTR themeName = isDarkMode ? L"DarkMode_Explorer" : L"";
+
+    HRESULT status = SetWindowTheme(_hWnd, themeName, nullptr);
+    if (status != 0) {
+        JWM_VERBOSE("Failed to SetWindowTheme");
+        return getCurrentTheme();
+    }
+    bool isOk = _setThemeInternal(_hWnd, theme, isDarkMode);
+    // It would be better to reset window theme if this fails.
+    return isOk ? theme : getCurrentTheme();
+}
+
+bool jwm::ThemeHelperWin32::_setThemeInternal(HWND hWnd, Theme theme,
+                                              bool isDarkMode) {
+    HMODULE hMod;
+    hMod = LoadLibrary(TEXT("user32.dll"));
+    if (!hMod) {
+        JWM_VERBOSE("Failed to get module handle for user32.dll");
+        return false;
+    }
+
+    jwm::FnSetWindowCompositionAttribute fn;
+    fn = (jwm::FnSetWindowCompositionAttribute)GetProcAddress(
+        hMod, "SetWindowCompositionAttribute");
+    if (!fn) {
+        JWM_VERBOSE(
+            "Failed to get proc address for SetWindowCompositionAttribute "
+            "function");
+        FreeLibrary(hMod);
+        return false;
+    }
+    jwm::WINDOWCOMPOSITIONATTRIBDATA data;
+    data.Attrib = WCA_USEDARKMODECOLORS;
+    data.pvData = &isDarkMode;
+    data.cbData = sizeof(&isDarkMode);
+
+    bool status = fn(hWnd, &data);
+    JWM_VERBOSE("SetWindowCompositionAttribute '" << status << "'");
+    FreeLibrary(hMod);
+    return status != FALSE;
+}
+
+// strict version check
+bool jwm::ThemeHelperWin32::_checkOSVersion() {
+    OSVERSIONINFOW osVersionInfo;
+    try {
+      osVersionInfo = jwm::SystemWin32::getOSVersion();
+    } catch (...){
+        // swallow
+        return false;
+    }
+
+    return osVersionInfo.dwMajorVersion == 10 &&
+           osVersionInfo.dwMinorVersion == 0 &&
+           osVersionInfo.dwBuildNumber >= 17763;
+}
+
+bool jwm::ThemeHelperWin32::_isDarkModeSupported() {
+    if (isHighContrast()) {
+        return false;
+    }
+    // NOTE: skip strict OS version check since JWM currently(Sep.2021) targets
+    // Windows 10+. Assume if your windows version is 10 or higher, it supports
+    // dark mode.
+    return IsWindows10OrGreater();
+}
+bool jwm::ThemeHelperWin32::isHighContrast() {
+    HIGHCONTRASTA highContrast;
+    highContrast.cbSize = sizeof(HIGHCONTRASTA);
+    highContrast.dwFlags = 0;
+    highContrast.lpszDefaultScheme = nullptr;
+    bool isOk = SystemParametersInfoA(SPI_GETHIGHCONTRAST, 0, &highContrast, 0);
+    if (!isOk) {
+        JWM_VERBOSE("Failed to get SystemParametersInfoA for high contrast");
+        return false;
+    }
+    JWM_VERBOSE("is HighContrast? '"
+                << ((HCF_HIGHCONTRASTON & highContrast.dwFlags) == 1) << "'");
+    return (HCF_HIGHCONTRASTON & highContrast.dwFlags) == 1;
+}

windows/cc/ThemeHelperWin32.hh

@@ -0,0 +1,38 @@
+#pragma once
+#include <PlatformWin32.hh>
+
+#include "ThemeHelper.hh"
+#include "ThemeHelperWin32.hh"
+
+namespace jwm {
+    typedef enum { WCA_USEDARKMODECOLORS = 26 } WINDOWCOMPOSITIONATTRIB;
+
+    typedef struct {
+        WINDOWCOMPOSITIONATTRIB Attrib;
+        PVOID pvData;
+        SIZE_T cbData;
+    } WINDOWCOMPOSITIONATTRIBDATA;
+
+    typedef bool(WINAPI *FnShouldAppsUseDarkMode)();
+    typedef bool(WINAPI *FnSetWindowCompositionAttribute)(
+        HWND, WINDOWCOMPOSITIONATTRIBDATA *);
+
+    class ThemeHelperWin32 final : public ThemeHelper {
+       public:
+           ThemeHelperWin32(HWND hWnd) { _hWnd = hWnd; };
+           ThemeHelperWin32() = default;
+           ~ThemeHelperWin32() = default;
+           Theme getCurrentTheme();
+           Theme setTheme(Theme theme);
+            // If screen is high contrast mode, disable dark mode.
+           bool isHighContrast();
+
+       private:
+           HWND _hWnd;
+           bool _checkOSVersion();
+           // check if OS is Windows 10 and build version >= 17763.
+           bool _isDarkModeSupported();
+           // This function sets window's title bar light/dark.
+           bool _setThemeInternal(HWND hWnd, Theme theme, bool isDarkMode);
+    };
+}  // namespace jwm