Old Virtual Pen Project History

31 May 2002

• While trying to debug the logic behind the style edition and cloning mechanisms, I hit a wall... It is nearly impossible to understand, yet maintain, the complexity involved in the current implementation. I see only one solution : develop a simpler mechanism (if this is possible).
• At noon, things were clear : I really have to redesign the attribute edition code. Spent part of the afternoon designing a new, simpler approach, where the core no longer does any magick behind the back of the front-end. Cloning will be the front-end's responsibility.

30 May 2002

• Updated Sink class to make every named sink a unique sink. Sinks with the same name map to the same instance... This makes enabling and disabling commands very easy. This required lots of changes in the VP.Forms namespace.
• Fixed a bug in object deletion. The order in which objects were deleted sometimes caused the undo not to move the objects back into the document.
• Making attribute edition available when objects are selected. This required grasping (again! -- I should definitively document the complex piece of code implemented in styled.cpp) how style cloning works.
• Chasing bugs...

29 May 2002

• Implemented the deletion of a selection. The simple DeleteObject command could not be used, since it did not deselect/reselect the objects; added DeleteSelObjects command, which can delete a list of selected objects in a single operation. Also modified the SelGrips attribute, so that it can be marked as deleted; this avoids changing too much the object structure when a selected object is deleted.
• The Sink class maintains information about the associated widgets.

28 May 2002

• The document view is now screen resolution aware. Class VP.FrontEnd.Controllers.DocView computes the document size [pixels] based on the document size [units], the screen resolution and the zoom factor.
• Fixed a few problems introduced yesterday while changing the coordinate systems of the document view. VP.Path.Grip.Record now also provides information about the exact document coordinates, not just the screen coordinates. This was needed for the Bézier curve edition.
• Added command GUI.DocView.SetZoom which can be used to change the zooming factor of the document view. It finally works !
• Added a new kind of adorner for the document view : DocViewAdorner.PageInfo, which can be used to put controls to the left of the horizontal scroll bar. The demo plug-in now also implements a zoom information label, which is displayed there.
• Cleaning up the selection chooser.

27 May 2002

• Finished refactoring, so that external plug-ins can put adorners to the document view and provide a magnetic grid feature. I have written a sample plug-in which draws adorners on the left and top of the document view; this will be the ideal base for a ruler... 
• Plug-ins can specify a GUI precedence attribute (VP.PIS.GUIPrecedenceAttribute) which is used to sort the plug-ins in a logical order, rather than using the default load order (which is arbitrary).
• The IFormCreator derived plug-ins don't necessarily show up in the Tools menu. If their ObjectClass string starts with a '*', then they won't be shown as interactive commands. Moreover, they get the opportunity to modify their attached command sink (to replace the default GUI.ShowForm with something different).
• The command sink now generates an Executing event before it executes the script, and an Executed command after it executed it. An IFormCreator derived plug-in could register an Executing handler in order to replace or complement the script execution.
• The front-end provides support for implicit command definition through sink script modification : if a sink's script is set to a string such as "#def:GUI.MakeFoo bar", VP.FrontEnd.Logic.SinkOverride will bind the command "GUI.MakeFoo bar" with the associated sink. When executing "GUI.MakeFoo bar", the sink's HandleClick method will be called. This will generate the Executing and Executed events, but will not execute the script itself, since it will be handled as a comment (#).
• Fixed a bug in the floating point parsing code in the core (it produced an overflow on numbers with a lot of digits after the decimal point).
• Finally implemented and tested the zoom for the document view. This required a few modifications. The rendering is now done in a different way, since in the original method, the dashed selections were zoomed too.

26 May 2002

• Sunday... no work.

25 May 2002

• Continuing refactoring :
  • VP.Path.Grip now provides standard EventHandler and EventArgs.
  • VP.FrontEnd.Controllers.DocView was extensively modified in order to have a cleaner event handling mechanism.
  • VP.FrontEnd.Logic.Application handles shutting down notifications with events.
  • VP.FrontEnd.Controllers.ToolsToolBar no longer uses the QueryDefObject/SetDefObject commands. It also stores the last tool used in the default settings.
  • VP.PIS.GUI.IObject now has Attach/Detach methods, which are used to bind the plug-in's event handlers to the document view controller's event sources.
  • VP.FrontEnd.Logic.Application handles shutting down with events. It also provides more events (such as ActiveDocViewChanging).
  • VP.CoreWrapper.Application.Access is no longer needed, since the plug-ins can talk directly to the front-end.
• Reorganised the CursorEvent class, which is now part of the VP.FrontEnd.Controllers namespace. It is extensible for the use of a graphic tablet (using additional Wintab information, such as pressure, tilt, etc.) thanks to the SetTabletInfo and GetTabletInfo methods.
• VP.Ucid.ID can now be initialised directly from a string.

24 May 2002

• Refactoring and cleaning up following classes :
  • VP.FrontEnd.Controllers.DocView.
  • VP.CoreWrapper.CallbackHub.
  • VP.PlugIn.GUI.AttributePanelAlpha.
• Refactored VP.Forms.Graphic.DocView(Scrollable) in order to support more than a single crosshairs cursor, which will become useful when constraining the main cursor coordinates to a grid, for instance.
• Added support for adorners in the document view, which can then be used to implement rulers, for instance.

23 May 2002

• Added buttons to select which object of a multiple object selection the user wants to work on. While doing so, improved the VP.Forms.Factory and VP.Forms.LayoutHelper classes.
• Working on multiple object selection : this had a lot of far-reaching implications in the GUI code. I now have a working version where the user can select which object is actively selected, but I am not sure that the implementation is as clean as it should be. I get a messy spaghetti like event handling structure, and I hate it.

22 May 2002

• The selections are no longer painted by the selection attribute : they are recorded in the render context and can therefore be redrawn very quickly (there is no need to walk through the document to animate the selected objects, for instance). VP::Render::Context implements RecordSelectionPath and DrawSelectionPath.
• Command RenderView can be configured to render only part of the document view (for instance, just the selected objects cached during a past update). The selection can now be animated with a rotating dashed line if the selection is marked as active.
• Added command SetSelBodyHilite to specify how the specified selected objects must be hilited (supported modes are None, Simple and Active).
• Changed how the default creation object is specified (every time command ObjectCreation gets executed, it also gets the UCID of the object to create; this avoids the strange problems which happened when the undo/redo was out of sync with the active tool, e.g. after loading a document).

21 May 2002

• Command DetectObjectsInBox returns both the object and its UCID, which allows the selector to keep track of how many different object classes are selected.
• Command SelectObjects returns the attributes which have been inserted into the objects.
• Added a GUI.OpMode for the plug-ins (method IObject.InstanciateGUI), which allows the plug-ins to know if they are to generate a GUI for object creation or for object edition. Moreover, the base plug-in object class generates a title which contains the number of selected objects and the number of objects with the matching UCID.
• Started changes in the selection handing, so that multiple object types can be selected and edited together. 

20 May 2002

• Testing the PointDef... commands. They seem to work as expected.
• Modified the interaction between VP::DocObj::BBox and VP::Render::Context; the bounding boxes are now stored as a stack  while rendering, which allows an easy restoration of the previous bounding box when leaving an object. It can also be used to identify more precisely to which block an attribute is bound.
• Methods VP::Render::Context::FindObjectAttributes and FindStyleAttributes now fill a VP::Render::AttributeDef array, which allows the caller to get more information about the attributes (such as where the attribute is located, which is needed to differentiate a local attribute from one applied to a parent wrapper).
• When creating points and objects, it is now possible to specify whether the undo/redo should be bound to the previous/next command in the command history. This was needed to handle the Bézier curve specificities.
• When loading a document, things get reset properly in the core and in the front-end.
• Implemented a new method, Cmd::Manager::Optimise, which can be used to force a command optimisation just after a command has been inserted into the command history. This is used by MoveObject and MoveGrip commands.
• Command MoveGrip now accepts several grip specifications for a single command, which is useful for the Bézier curve (several grip movements can be associated and optimised if needed, which would be much more complicated to implement with split commands).
• Added support for dynamically loading C++ plug-ins (currently by executing command "app.LoadPlugIn xyz.dll"). Should this kind of loading be automatic ?

19 May 2002

• Added command CreateObject which can be used to create any kind of object based on its UCID.
• Continuing work on point definition attributes.

18 May 2002

• No work on Virtual Pen today. A lot of work nevertheless.

17 May 2002

• Added command UpdateMovePointCreation, which allows the Bézier curve creator to update the secondary points instead of only the last one. This allowed me to finish the Bézier curve creation process (with symetrical secondary point creation).

• Designing a new attribute which can be used to associate special properties (or attributes) to points. The points can be real (as in a polygonal line or Bézier curve) or virtual (as in a rectangle, where 2 points do not really exist in the object description, or as in a polygon, where only one really exists).
• Implemented the VP::DocAttr::PointDef class, its manager PointDefManager and its specific commands (InsertPtDefXxx, ReadPtDef, WritePtDefXxx, RemovePtDef). The commands are not all finished yet.

16 May 2002

• Made sure the window got redrawn when the user drags grips or figures, since otherwise the window invalidation would simply accumulate and no redrawing would happen under heavy load...
• Rewritten the multi-point creation class; it is no longer dependent on O-Line, but is now a common core base class (VP::DocObj::MultiPt and VP::DocObj::MultiPtCreator). This allows o.bezier, o.line and o.polyline to use a common base class.
• Added command QueryObjectUcid, needed in order to identify the object being edited. This was needed in order to call the proper event handler when an object's grips got moved.
• The event handlers are now differenciated between object creation (GUI.IEdition) and object edition (GUI.ICreation). The Bézier plug-in implements its own IEdition and ICreation event handlers to support smart grip positioning and moving.
• Reparented the VP.CoreWrapper.Unit and VP.CoreWrapper.Grip namespaces to VP.Unit and VP.Path.Grip, which is much more consistent with what is used in the C++ implementation.
• Changed the namespace VP.PlugInServices to VP.PIS which is much shorter.

15 May 2002

• Continuing work on Bézier curve and its far reaching implications.
• The plug-ins can handle grip movements (HandleMoveGrip).
• Grips are now defined by following information :
  • An object index.
  • A grip index (consecutive values from 0 to n).
  • A sequence ID which can be used to identify the grip more precisely; this is new.
  • X and Y coordinates. What these coordinates represent is not yet precisely defined (pixels on the screen or real world coordinates with units ?) 
• Added command DelayNotifications.
• Updating the transformation mechanisms (classes in the VP::DocTrans namespace). They are responsible for the forward and backward coordinate transformations. A point is now processed with its original units and is no longer converted to points to do the math.
• I have drawn my first Blupi with VP today. It is an ugly Blupi, but Blupi nevertheless :

• Afternoon off duty.

14 May 2002

• Worked on the Bézier curve. It must be able to draw special items, such as extra lines, when the figure is selected or being created. The Bézier curve also needs special care to be able to drag primary grips and move the associated secondary grips with it.
• Worked for the .NET installation program (avoiding that the wrong version of .NET gets installed on Windows 98). This is not VP related...
• Finished reading OTLS (OpenType Layout) and related documentation from the Microsoft Typography page. Great stuff, but few examples. And the hz program from Peter Karov is full of good ideas. See links of previous day for details.
• Very long phone call with Daniel Roux... He will be working on plug-ins for VP soon !

13 May 2002

• Updated DocView::RenderView to be more generalised. It can now be used to do both rendering and detection. This feature is used by command DetectObjectsAtPos.
• The CallbackHub now provides an access to a default HDC for the core, which can be used in contexts where the core does not know that it should provide a HDC or GDI+ graphics context.
• Adding Bézier curve support. This required the introduction of method AddBezier in the path operator and related classes.
• Finished reading the excellent book The Elements of Typographic Style written by Robert Bringhurst. This lead me to the HZ algorithm and variations of it for smart justification (still better than TeX). And I also returned to Microsoft's Typography which contains lots of interesting stuff, such as Open Type, Uniscribe, etc. Text edition might turn out to be very complex if I want to benefit from modern fonts and all the information on contextual kerning and substitutions (e.g. for ligatures). 

12 May 2002

• Commands such as  DetectObjectsInBox, DetectObjectsAtPos, etc. should be only applied to the visible roots of the view the user is working on. This is now possible thanks to command DetectRootsAtPos.
• Implemented command QuerySelectedObjects.
• Fixed bug in selection mechanism (command QueryObjectSelState was not always finding the SelGrips attribute properly).

11 May 2002

• Removing useless code in the core document manager. Following files had become obsolete and were removed :
  • SelManager, the selection manager. All selection processing is done by the front-end and by the selection commands.
  • DocObj::Selector, the selection helper.
  • Command GripNotification has become useless.
• Every DocView instance now gets its own Render::Context. Thanks to this change, a view can cache some state (such as the path of the selected objects) and this results in a significant speed-up and simplification of some commands.
• Class GripManager was very much simplified. Most of the work is done in the front-end. The O-Line was also simplified thanks to the plug-in infrastructure, which provides the event handling.
• Adapted the bootstrap sample from Microsoft in order to make a .NET installer for the CRESUS CD-ROM. Nothing to do with VP, but I will be able to re-use this program when VP ships.
• Added more debugging information for the DebugDumpDocument command : now display the textual representation of the Info::Generic objects.
• Added command DetectRootsAtPos.

10 May 2002

• Clean up (new ideas section) and administrative work. I hate doing this, it makes me feel unproductive.
• Finished reading a document about the Aqua user interface.
• Design phase.

09 May 2002

• I did not work for VP today.
• Read documentation on the Aqua user interface (Macintosh OS X). Nice ideas.

08 May 2002

• Reworking the event transmission from front end to core and updating the creation process, so that plug-ins can have access to the whole event chain.
• Think about the graphic tablets... They seem to adhere to a standardised API known as Wintab.
• Implemented support for generalised unit representation and transformation in C#. This is useful to avoid having to talk to the core to get the units converted (VP.CoreWrapper.Unit.Value).
• More work on CRESUS Safe...
• Submitted my h/cpp switching macro to www.CodeProject.com. The article is here.

07 May 2002

• Provided the plug-ins with the possibility to define their custom area in the attribute palette. This required a cleaner separation between the IAttribute and IObject interfaces, thus I added an IUcid interface which can be used for all UCID related plug-ins.
• Again, I did not expect to work on CRESUS Safe project. Denis started to integrate it with EpBackup, and thus required a few changes (and found a few bugs on Windows 98 and with another SMTP server). There is now a German version too of this non-VP tool.

06 May 2002

• Changed the FrontEnd application to a class library. This was needed, since plug-ins had to access some of the application types and classes, and .NET does not allow a DLL to reference an EXE. A new (very small) VirtualPen.exe serves as the launching application. The PlugInServices class library was merged with the FrontEnd.
• Extracted the color, alpha and line width edition panels and put them into separate plug-ins.
• Worked for CRESUS Safe project... This is not VP.

03-05 May 2002

• I took a (well deserved ?) break... Alas, the weather was very rainy, even in Intragna (TI). So I had no choice but to think about design questions in VP.

02 May 2002

• Worked on a non-VP project today (CRESUS Safe, aka CryptoBackup).
• Bug hunting :
  • When drawing a polygonal figure, undoing a point and closing the figure, a fork happens in the command history. This seemed to cause some trouble, but it was in fact a dead-end... The problem was that when undoing a point creation, the first point of the polygonal line was re-inserted as a hot grip. The original one (numbered 0) was lost and not removed at the end of the creation, which caused the front-end to think there still was a valid grip, etc.  
  • Hot grips got not removed properly when the core switched from creation to idle mode. This also sometimes produced crashes (I had broken VP::CallbackHub::CallGripDefinition while fixing things on 22 April).

01 May 2002

• No Virtual Pen today. Experimenting some unknown areas of the .NET framework. 

History of previous months.