Camelot: SGScrollDragTarget Class Reference

00183 {
00184     // Weed out events that we are not interested in
00185     switch(Event)
00186     {
00187         case DRAGEVENT_ABORT:
00188         case DRAGEVENT_COMPLETED:
00189             // Just claim the event as ours.
00190             // We don't get these events unless the pointer is over us, so we don't do
00191             // anything here - see the deinitialise handler
00192             return(TRUE);
00193 
00194         case DRAGEVENT_INITIALISE:
00195         case DRAGEVENT_DEINITIALISE:
00196         case DRAGEVENT_MOUSEMOVED:
00197         case DRAGEVENT_MOUSESTOPPED:
00198         case DRAGEVENT_MOUSEIDLE:
00199             // We want these events, so break to drop through and process them
00200             break;
00201 
00202         default:
00203             // An unknown/unwanted event type - it could be dangerous to do something on
00204             // an unknown event, so we won't!
00205             return(TRUE);
00206     }
00207 
00208     // Cast the draginfo into the correct type
00209     SGScrollDragInfo *DragInfo = (SGScrollDragInfo *) pDragInfo;
00210 
00211     // FALSE if we aren't dragging, but just handling auto-repeat
00212     BOOL NotAutoRepeat = (DragInfo->GetDragType() == SGDRAG_SAUSAGE);
00213 
00214     SGDisplayRootScroll *Root   = DragInfo->GetDragRootNode();
00215     SGMiscInfo *MiscInfo        = DragInfo->GetDragMiscInfo();
00216     SuperGallery *ParentGallery = Root->GetParentGallery();
00217 
00218     // Convert the OilCoord into a DocCoord, and convert into displaylist coords
00219     DocCoord MousePos(pMousePos->x, pMousePos->y);
00220     ParentGallery->ConvertToVirtualCoords(MiscInfo, &MousePos);
00221 
00222     // And calculate the relevant rectangles...
00223     DocRect UpButton;
00224     DocRect DownButton;
00225     DocRect SausageRect;
00226     DocRect PageUp;
00227     DocRect PageDown;
00228     DocRect ScrollRect;
00229     Root->CalculateScrollRects(MiscInfo, TRUE,
00230                                  &UpButton, &DownButton, &SausageRect,
00231                                  &PageUp, &PageDown, &ScrollRect);
00232 
00233     if (Event == DRAGEVENT_MOUSEMOVED && NotAutoRepeat)
00234     {
00235         // Dragging the scroll sausage
00236 
00237         // Get the offset - the scroll sausage should try to move this point of the
00238         // sausage (measured in millipoints from the top of the sausage) to lie under
00239         // the mouse pointer position if possible.
00240         INT32 AnchorOffset = DragInfo->GetDragAnchorOffset();
00241 
00242         INT32 ScrollWindowTo;
00243         
00244         if (SausageRect.Height() <= SausageRect.Width())
00245         {
00246             // The sausage is a minimum-size square, so now does not proportionally represent
00247             // the displayed area of the window. Thus, we need to use the top position of the
00248             // bar in (barheight - sausageheight) as a fractional scroll between 0 and 
00249             // (ScrollExtent - WindowHeight)
00250             ScrollWindowTo = (INT32) (
00251                                     ( ((double) (ScrollRect.hi.y - (MousePos.y + AnchorOffset))) / 
00252                                         (double) (ScrollRect.Height() - SausageRect.Height()) ) *
00253                                             (double) (Root->GetCachedListExtent() - MiscInfo->WindowHeight)
00254                                     );
00255         }
00256         else
00257         {
00258             // The bar represents the fraction of visible area to extent, so we work out the
00259             // fractional position of the top of the bar, and that gives the position to scroll
00260             // the top of the displayed area to.
00261             ScrollWindowTo = (INT32) (
00262                                     ( ((double) (ScrollRect.hi.y - (MousePos.y + AnchorOffset))) / 
00263                                         (double) ScrollRect.Height() ) *
00264                                             (double) Root->GetCachedListExtent()
00265                                     );
00266         }
00267 
00268         Root->SetScrollOffset(ScrollWindowTo, MiscInfo);
00269         return(TRUE);
00270     }
00271 
00272 
00273     // The drag must therefore be to implement simple AutoRepeat on a button or page-scroll.
00274     // We only bother scrolling if:
00275     //      1) Event is 'initialise' (so it scrolls immediately the button goes down)
00276     //      2) Event is 'deinitialise' (so we must ensure all buttons are popped up)
00277     //      3) Or if it is time for another autorepeat
00278     if (Event != DRAGEVENT_INITIALISE   && 
00279         Event != DRAGEVENT_DEINITIALISE &&
00280         !Timer.Elapsed(AUTOREPEATTIME))
00281     {
00282         // No need to update just now. Return, claiming this event
00283         return(TRUE);
00284     }
00285 
00286     const INT32 ClickScroll = 12000;        // Millipoint distance to scroll for a button click
00287     INT32 ScrollBy = 0;                 // Set this to the amount by which to scroll
00288 
00289     Timer.Sample();                     // Update the autorepeat timer
00290 
00291     switch (DragInfo->GetDragType())
00292     {
00293         case SGDRAG_SCROLLUP:
00294             if (Event == DRAGEVENT_DEINITIALISE)
00295             {
00296                 // Drag completed: Unindent the scroll button
00297                 Root->IndentedButton = IBUTTON_NONE;
00298                 ParentGallery->ForceRedrawOfArea(&UpButton);
00299                 ParentGallery->PaintListNow();
00300             }
00301             else if (UpButton.ContainsCoord(MousePos))
00302             {
00303                 ScrollBy = -ClickScroll;
00304 
00305                 // Indent the scroll button
00306                 Root->IndentedButton = IBUTTON_UP;
00307                 ParentGallery->ForceRedrawOfArea(&UpButton);
00308                 ParentGallery->PaintListNow();
00309             }
00310             break;
00311 
00312 
00313         case SGDRAG_SCROLLDOWN:
00314             if (Event == DRAGEVENT_DEINITIALISE)
00315             {
00316                 // Drag completed: Unindent the scroll button
00317                 Root->IndentedButton = IBUTTON_NONE;
00318                 ParentGallery->ForceRedrawOfArea(&DownButton);
00319                 ParentGallery->PaintListNow();
00320             }
00321             else if (DownButton.ContainsCoord(MousePos))
00322             {
00323                 ScrollBy = ClickScroll;
00324 
00325                 // Indent the scroll button
00326                 Root->IndentedButton = IBUTTON_DOWN;
00327                 ParentGallery->ForceRedrawOfArea(&DownButton);
00328                 ParentGallery->PaintListNow();
00329             }
00330             break;
00331 
00332 
00333         case SGDRAG_PAGEUP:
00334             if (PageUp.IsValid() && PageUp.ContainsCoord(MousePos))
00335             {
00336                 ScrollBy = MiscInfo->WindowHeight - ClickScroll;
00337                 if (ScrollBy < 0)
00338                     ScrollBy = ClickScroll;
00339 
00340                 ScrollBy = -ScrollBy;
00341             }
00342             break;
00343 
00344 
00345         case SGDRAG_PAGEDOWN:
00346             if (PageDown.IsValid() && PageDown.ContainsCoord(MousePos))
00347             {
00348                 ScrollBy = MiscInfo->WindowHeight - ClickScroll;
00349                 if (ScrollBy < 0)
00350                     ScrollBy = ClickScroll;
00351             }
00352             break;
00353 
00354         default:
00355             break;
00356     }
00357 
00358     if (Event != DRAGEVENT_DEINITIALISE && ScrollBy != 0)
00359     {
00360         if (DragInfo->IsAdjustDrag())   // If adjust-drag, reverse scroll direction
00361             ScrollBy = -ScrollBy;
00362 
00363         Root->SetScrollOffset(Root->GetScrollOffset() + ScrollBy, MiscInfo);
00364     }
00365 
00366     // We always claim all events during this drag (it is not a drag to a particular place
00367     // to move an object - really we're using the drag system to "capture" the mouse)
00368     return(TRUE);
00369 }

Public Member Functions
	SGScrollDragTarget (DialogOp *TheDialog, CGadgetID TheGadget=NULL)
	Constructor.
virtual UINT32	GetCursorID ()
	Base Method to set cursor over this target.
virtual BOOL	GetStatusLineText (String_256 *TheText)
	Provide status line text for this target.
Protected Member Functions
virtual BOOL	ProcessEvent (DragEventType Event, DragInformation pDragInfo, OilCoord pMousePos, KeyPress *pKeyPress)
	Event Handler for SuperGallery scrollbar drag events.
Protected Attributes
MonotonicTime	Timer
Friends
class	DragManagerOp
SGScrollDragTarget Class Reference

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation
