MiniGUI API Reference (MiniGUI-Processes)  v3.2.0
A mature and proven cross-platform GUI system for embedded and smart IoT devices
Functions
Clipping operations

Functions

MG_EXPORT void GUIAPI ExcludeClipRect (HDC hdc, const RECT *prc)
 Excludes the specified rectangle from the current visible region of a DC. More...
 
MG_EXPORT void GUIAPI IncludeClipRect (HDC hdc, const RECT *prc)
 Includes the specified rectangle to the current visible region of a DC. More...
 
MG_EXPORT BOOL GUIAPI PtVisible (HDC hdc, int x, int y)
 Checks whether a point is visible. More...
 
MG_EXPORT void GUIAPI ClipRectIntersect (HDC hdc, const RECT *prc)
 Intersects the specified rectangle with the visible region of the DC. More...
 
MG_EXPORT void GUIAPI SelectClipRect (HDC hdc, const RECT *prc)
 Sets the visible region of a DC to be a rectangle. More...
 
MG_EXPORT int GUIAPI SelectClipRegionEx (HDC hdc, const CLIPRGN *pRgn, int fnMode)
 Combines the specified region with the current clipping region using the specified mode. More...
 
MG_EXPORT void GUIAPI SelectClipRegion (HDC hdc, const CLIPRGN *pRgn)
 Sets the visible region of a DC to be a region. More...
 
MG_EXPORT int GUIAPI OffsetClipRegion (HDC hdc, int nXOffset, int nYOffset)
 Moves the clipping region of a device context by the specified offsets. More...
 
MG_EXPORT void GUIAPI GetBoundsRect (HDC hdc, RECT *pRect)
 Retrieves the bounding rectangle of the current visible region of a DC. More...
 
MG_EXPORT BOOL GUIAPI RectVisible (HDC hdc, const RECT *pRect)
 Checks whether the specified rectangle is visible. More...
 
MG_EXPORT int GUIAPI GetClipBox (HDC hdc, RECT *clipbox)
 Retrieves the bounding rectangle of the current clipping region of a DC. More...
 
MG_EXPORT int GUIAPI GetClipRegion (HDC hdc, CLIPRGN *cliprgn)
 Gets the current clipping region of a DC. More...
 

Detailed Description

Function Documentation

void GUIAPI ClipRectIntersect ( HDC  hdc,
const RECT prc 
)

Intersects the specified rectangle with the visible region of the DC.

This function intersects the specified rectangle prc with the visible region of the device context hdc.

Parameters
hdcThe device context.
prcPointer to the rectangle.
See also
IncludeClipRect, ExcludeClipRect, Region operations
void GUIAPI ExcludeClipRect ( HDC  hdc,
const RECT prc 
)

Excludes the specified rectangle from the current visible region of a DC.

This function excludes the specified rect prc from the current visible region of the device context hdc.

Parameters
hdcThe device context.
prcThe rectangle to be excluded.
See also
IncludeClipRect, Region operations
void GUIAPI GetBoundsRect ( HDC  hdc,
RECT pRect 
)

Retrieves the bounding rectangle of the current visible region of a DC.

This function retrieves the bounding rectangle of the current visible region of the specified device context hdc, and returned through pRect.

Parameters
hdcThe device context.
pRectThe bounding rectangle will be returned through this buffer.
See also
Region operations
int GetClipBox ( HDC  hdc,
RECT clipbox 
)

Retrieves the bounding rectangle of the current clipping region of a DC.

This function retrieves the bounding rectangle of the current clipping region of the specified device context hdc, and returned through clipbox.

Parameters
hdcThe device context.
clipboxThe bounding rectangle will be returned through this buffer.
Returns
-1 for error, else the type of clipping region, can be one of the following values:
  • NULLREGION
    A null region.
  • SIMPLEREGION
    A simple region.
  • COMPLEXREGION
    A complex region.
See also
GetBoundsRect
int GetClipRegion ( HDC  hdc,
CLIPRGN cliprgn 
)

Gets the current clipping region of a DC.

This function gets the current clipping region of the specified device context hdc, and returned through cliprgn.

Parameters
hdcThe device context.
cliprgnThe clipping region will be returned through this buffer.
Returns
-1 for error, else the type of clipping region, can be one of the following values:
  • NULLREGION
    A null region.
  • SIMPLEREGION
    A simple region.
  • COMPLEXREGION
    A complex region.
See also
GetClipBox, SelectClipRegion
void GUIAPI IncludeClipRect ( HDC  hdc,
const RECT prc 
)

Includes the specified rectangle to the current visible region of a DC.

This function includes the specified rectangle prc to the current visible region of the device context hdc.

Parameters
hdcThe device context.
prcThe rectangle to be included.
See also
ExcludeClipRect, Region operations
int GUIAPI OffsetClipRegion ( HDC  hdc,
int  off_x,
int  off_y 
)

Moves the clipping region of a device context by the specified offsets.

This function moves the clipping region of a device context hdc by the specified offsets (off_x, off_y).

Parameters
hdcHandle to the device context.
off_xSpecifies the number of device units to move left or right.
off_ypecifies the number of device units to move up or down.
Returns
The return value specifies the new clipping region's complexity; it can be one of the following values.
Return values
NULLREGIONRegion is empty.
SIMPLEREGIONRegion is a single rectangle.
COMPLEXREGIONRegion is more than one rectangle.
-1An error occurred.
See also
SelectClipRegion
BOOL GUIAPI PtVisible ( HDC  hdc,
int  x,
int  y 
)

Checks whether a point is visible.

This function checks whether the point specified by (x,y) is visible, i.e. it is within the current visible clipping region of the device context hdc.

Parameters
hdcThe device context.
xx,y: The coordinates of the point.
yx,y: The coordinates of the point.
Returns
TRUE for visible, else for not.
See also
RectVisible, Region operations
BOOL GUIAPI RectVisible ( HDC  hdc,
const RECT pRect 
)

Checks whether the specified rectangle is visible.

This function checks whether the rectangle pointed to by pRect is visible, i.e. it is intersected with the current visible region of the device context hdc.

Parameters
hdcThe device context.
pRectPointer to the rectangle.
See also
PtVisible, Region operations

Example:

/*
* Use RectVisible to optimize the repaint of the window.
*/
case MSG_PAINT:
{
HDC hdc = BeginPaint (hWnd);
for (j = 0; j < 10; j ++) {
if (RectVisible (hdc, rcs + j)) {
FillBox (hdc, rcs[j].left, rcs[j].top, rcs [j].right, rcs [j].bottom);
}
}
EndPaint (hWnd, hdc);
return 0;
}
void GUIAPI SelectClipRect ( HDC  hdc,
const RECT prc 
)

Sets the visible region of a DC to be a rectangle.

This function sets the visible region of the device context hdc to the rectangle pointed to by prc.

Parameters
hdcThe device context.
prcPointer to the rectangle.
See also
SelectClipRegion, Region operations
void GUIAPI SelectClipRegion ( HDC  hdc,
const CLIPRGN pRgn 
)

Sets the visible region of a DC to be a region.

This function sets the visible region of the device context hdc to the region pointed to by pRgn.

Parameters
hdcThe device context.
pRgnPointer to the region.
See also
SelectClipRect, GetClipRegion, Region operations
int GUIAPI SelectClipRegionEx ( HDC  hdc,
const CLIPRGN pRgn,
int  fnMode 
)

Combines the specified region with the current clipping region using the specified mode.

This function combines the specified region with the current clipping region using the specified mode.

If an error occurs when this function is called, the previous clipping region for the specified device context is not affected.

The SelectClipRegionEx function assumes that the coordinates for the specified region are specified in device units.

Only a copy of the region identified by the pRgn parameter is used. The region itself can be reused after this call or it can be deleted.

Parameters
hdcHandle to the device context.
pRgnPointer to the region to be selected. This handle can only be NULL when the RGN_COPY mode is specified.
fnModeSpecifies the operation to be performed. It must be one of the following values:
  • RGN_AND
    The new clipping region combines the overlapping areas of the current clipping region and the region identified by pRgn.
  • RGN_COPY
    The new clipping region is a copy of the region identified by pRgn. This is identical to SelectClipRegion. If the region identified by pRgn is NULL, the new clipping region is the default clipping region (the default clipping region is a null region).
  • RGN_DIFF
    The new clipping region combines the areas of the current clipping region with those areas excluded from the region identified by hrgn.
  • RGN_OR
    The new clipping region combines the current clipping region and the region identified by hrgn.
  • RGN_XOR
    The new clipping region combines the current clipping region and the region identified by hrgn but excludes any overlapping areas.
Returns
The return value specifies the new clipping region's complexity; it can be one of the following values.
Return values
NULLREGIONRegion is empty.
SIMPLEREGIONRegion is a single rectangle.
COMPLEXREGIONRegion is more than one rectangle.
-1An error occurred.
See also
SelectClipRect, SelectClipRegion, GetClipRegion, Region operations