HighContrastMode
Defines whether the tree control honors the Windows High Contrast accessibility setting.
C
void WINAPI SftTree_SetHighContrastMode(HWND hwndCtl, int mode);
int WINAPI SftTree_GetHighContrastMode(HWND hwndCtl);
BOOL WINAPI SftTree_IsHighContrastActive(HWND hwndCtl);
void WINAPI SftTreeSplit_SetHighContrastMode(HWND hwndCtl, int mode);
int WINAPI SftTreeSplit_GetHighContrastMode(HWND hwndCtl);
BOOL WINAPI SftTreeSplit_IsHighContrastActive(HWND hwndCtl);
C++
void CSftTree::SetHighContrastMode(int mode);
int CSftTree::GetHighContrastMode() const;
BOOL CSftTree::IsHighContrastActive() const;
void CSftTreeSplit::SetHighContrastMode(int mode);
int CSftTreeSplit::GetHighContrastMode() const;
BOOL CSftTreeSplit::IsHighContrastActive() const;
Parameters
hwndCtl
The window handle of the tree control.
mode
Defines the high contrast mode setting. mode can be one of the following values:
| SFTTREE_HIGHCONTRAST_OFF | The tree control ignores the Windows High Contrast setting and renders normally, using the tree control's configured colors and themes. |
| SFTTREE_HIGHCONTRAST_ON | The tree control always renders using the Windows system color palette (COLOR_WINDOW, COLOR_WINDOWTEXT, COLOR_HIGHLIGHT, etc.) as if Windows High Contrast were active. |
| SFTTREE_HIGHCONTRAST_AUTO | The tree control follows the current Windows High Contrast accessibility setting and switches automatically when the user changes it. This is the default. |
Returns
GetHighContrastMode returns a value indicating the current high contrast mode setting (SFTTREE_HIGHCONTRAST_OFF, SFTTREE_HIGHCONTRAST_ON or SFTTREE_HIGHCONTRAST_AUTO).
IsHighContrastActive returns TRUE if high contrast rendering is currently in effect on the tree control, otherwise FALSE. When mode is SFTTREE_HIGHCONTRAST_AUTO, the return value reflects the current Windows accessibility setting.
Comments
The SetHighContrastMode, GetHighContrastMode and IsHighContrastActive functions define and retrieve a tree control's high contrast mode setting. The default is SFTTREE_HIGHCONTRAST_AUTO so accessibility compliance is automatic; applications can opt out with SFTTREE_HIGHCONTRAST_OFF when a fully custom visual design is required.
When high contrast rendering is active, caller-supplied color overrides set with SetCtlColors, per-column colors, permanent background color, selection colors, grid line colors and odd-row colors are ignored on the default render path. The control instead uses the matching Windows system color (COLOR_WINDOW for backgrounds, COLOR_WINDOWTEXT for text, COLOR_HIGHLIGHT / COLOR_HIGHLIGHTTEXT for selection, COLOR_BTNSHADOW for , etc.), complying with Microsoft's High Contrast guidance that the user's chosen contrast theme must not be overridden by the application.
Windows themes are also suppressed in high contrast mode - fThemed is FALSE on both SFTTREE_OWNERDRAW callbacks and in internal header / footer rendering, so paint falls back to the non-themed GDI path that honors system colors.
When mode is SFTTREE_HIGHCONTRAST_AUTO, the tree control tracks WM_SETTINGCHANGE / SPI_SETHIGHCONTRAST notifications from Windows and re-renders automatically when the user toggles the accessibility setting. A SFTTREEN_HIGHCONTRAST_CHANGED notification is sent to the parent window each time the active state flips so the application can repaint other UI to match.
Owner-draw callbacks receive the current state in SFTTREE_OWNERDRAW's fHighContrast field. The strict color remap described above applies only to the default render path; owner-draw code is responsible for its own high contrast compliance.
See Also C/C++ API | Categories | Notifications
On
Off