src/Utils/Theme.h

   1 // TortoiseGit - a Windows shell extension for easy version control
   2
   3 // Copyright (C) 2023 - TortoiseGit
   4 // Copyright (C) 2020-2021 - TortoiseSVN
   5
   6 // This program is free software; you can redistribute it and/or
   7 // modify it under the terms of the GNU General Public License
   8 // as published by the Free Software Foundation; either version 2
   9 // of the License, or (at your option) any later version.
  10
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software Foundation,
  18 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 //
  20 #pragma once
  21 #include "registry.h"
  22 #include <unordered_map>
  23 #include <functional>
  24 #include <optional>
  25 #pragma warning(push)
  26 #pragma warning(disable : 4458) // declaration of 'xxx' hides class member
  27 #include <gdiplus.h>
  28 #pragma warning(pop)
  29
  30 using ThemeChangeCallback = std::function<void()>;
  31
  32 /**
  33  * Singleton to handle Theme related methods.
  34  * provides callbacks to allow different parts of the app
  35  * to receive notifications when the theme changes.
  36  */
  37 class CTheme
  38 {
  39 private:
  40         CTheme();
  41         ~CTheme();
  42
  43 public:
  44         static CTheme& Instance();
  45
  46         // cf. src/TortoiseUDiff/UDiffColors.h, src/SshAskPass/SshAskPass.cpp and src/TortoiseGitBlame/BlameIndexColors.h
  47         static const COLORREF darkBkColor = 0x202020;
  48         static const COLORREF darkBkHotColor = 0x404040;
  49         static const COLORREF darkTextColor = 0xDDDDDD;
  50         static const COLORREF darkDisabledTextColor = 0x808080;
  51
  52         /// call this on every WM_SYSCOLORCHANGED message
  53         void OnSysColorChanged();
  54         /// returns true if dark mode is even allowed. We only allow dark mode on Win10 1809 or later.
  55         bool IsDarkModeAllowed();
  56         /// sets the theme and calls all registered callbacks.
  57         /// if \force is true, all Callback functions are called whether the mode changed or not
  58         void SetDarkTheme(bool b = true, bool force = false);
  59         /// returns true if dark theme is enabled. If false, then the normal theme is active.
  60         bool IsDarkTheme() const;
  61         /// returns true if high contrast mode is on
  62         bool IsHighContrastMode() const;
  63         /// returns true if high contrast mode is on, and the color scheme is dark
  64         bool IsHighContrastModeDark() const;
  65         /// converts a color to the theme color. For normal theme the \b clr is returned unchanged.
  66         /// for dark theme, the color is adjusted in brightness.
  67         COLORREF GetThemeColor(COLORREF clr, bool fixed = false) const;
  68         Gdiplus::Color GetThemeColor(Gdiplus::Color clr, bool fixed = false) const;
  69         /// registers a callback function that's called for every theme change.
  70         /// returns an id that can be used to unregister the callback function.
  71         int RegisterThemeChangeCallback(ThemeChangeCallback&& cb);
  72         /// unregisters a callback function.
  73         bool RemoveRegisteredCallback(int id);
  74
  75         /// sets the theme for a whole dialog. For dark mode, the
  76         /// windows are subclassed if necessary. For normal mode,
  77         /// subclassing is removed to ensure the behavior is
  78         /// identical to the original.
  79         bool SetThemeForDialog(HWND hWnd, bool bDark);
  80
  81         static void RGBToHSB(COLORREF rgb, BYTE& hue, BYTE& saturation, BYTE& brightness);
  82         static void RGBtoHSL(COLORREF color, float& h, float& s, float& l);
  83         static COLORREF HSLtoRGB(float h, float s, float l);
  84
  85         static std::optional<LRESULT> HandleMenuBar(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
  86
  87 private:
  88         void Load();
  89         static BOOL CALLBACK AdjustThemeForChildrenProc(HWND hwnd, LPARAM lParam);
  90         static LRESULT CALLBACK ListViewSubclassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
  91         static LRESULT CALLBACK ComboBoxSubclassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
  92         static LRESULT CALLBACK MainSubclassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
  93         static LRESULT CALLBACK ButtonSubclassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
  94         static LRESULT CALLBACK AutoSuggestSubclassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
  95
  96 private:
  97         bool m_bLoaded = false;
  98         bool m_dark = false;
  99         bool m_isHighContrastMode = false;
 100         bool m_isHighContrastModeDark = false;
 101         bool m_bDarkModeIsAllowed = false;
 102         std::unordered_map<int, ThemeChangeCallback> m_themeChangeCallbacks;
 103         int m_lastThemeChangeCallbackId = 0;
 104         CRegStdDWORD m_regDarkTheme;
 105         static HBRUSH s_backBrush;
 106         static HBRUSH s_backHotBrush;
 107 };