User Tools

Site Tools


TGIS_ViewerWndHelper class

DK11 for Delphi | GisViewerWndHelper.TGIS_ViewerWndHelper | Classes | Constructors | Fields | Methods | Properties

Windows helper for operation like zoom, drag etc.

Available also on: .NET | Java.


// Delphi
  TGIS_ViewerWndHelper = class( TGIS_ObjectDisposable )
// C++ Builder
class PASCALIMPLEMENTATION TGIS_ViewerWndHelper : public TGIS_ObjectDisposable


→ TObject → TGIS_ObjectDisposable


Inherited Overrides Protected
Name Visibility Description
Create(TGIS_Viewer; TGIS_ViewerWndHelperRunEvent; TGIS_ViewerWndHelperSynchronizeEvent) public Create an instance
Create(TGIS_Viewer; TGIS_ViewerWndHelperRunEvent; TGIS_ViewerWndHelperSynchronizeEvent; TGIS_ViewerWndHelperSimpleEvent) public Create an instance


Inherited Protected
Name Visibility Description
GestureState public Status of gesture: is it active etc.


Inherited Overrides Protected
Name Visibility Description
ActualExtent public Actual extent of a map including current scale etc.
DoDrag public Drag a cache bitmap.
DoFullExtent public Perform animation of placing map in a full extent.
DoZoom(Double; Double; Double; Boolean; Boolean) public Zoom a cache bitmap by center point.
DoZoom(Double; Double; Double; Double) public Zoom a cache bitmap by zooming rectangle.
FitScreenAnimation public Animate cache bitmap to fit it properly into the window.
GestureActive public Gesture activity status.
GestureBegin public Start gesture.
GestureCancelLongTap public Cancel log tap gesture.
GestureEnd public Finalize gesture.
GestureMouseDown public Start operation upon MouseDown gesture.
GestureMouseMove public Start operation upon MouseMove gesture.
GestureMouseUp public Start operation upon MouseUp gesture.
GestureNoMovement public Gesture movement status.
GestureRecordMovement public Add movement to gesture engine.
IsScaled public Cached bitmap scaling sate.
Reset public Reset context to actual cache bitmap size and actual VisibleExtent of the map
ResetDelayedTime public Reset Delayed update threshold to original value.
ScaledRect(Single) public Provides rectangle used to scale a cached bitmap upon Paint.
ScaledRect(TGIS_Extent; Double; Double; Single) public Provides rectangle used to scale a cache bitmap upon Paint.
SetVisibleExtent public Set VisibleExtent based on current position and size of cached bitmap
UpdateCancel public Cancel any pending full map updates.
UpdateDelayed public Perform delayed map update.
UpdateImmediate public Force immediate map update.


Inherited Protected
Name Visibility Description
DelayedTime public Delayed update threshold in milliseconds.
KeepScale public True if a viewer should maintain scale upon resize.
PendingUpdate public True if any timer based update is undergoing.

2020/01/31 01:09