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2.3.2.1 Frames and Facets

   The logical structure of a document, which underlies its graphical 
   presentation, consists of the embedding relationships among its parts and 
   their frames as shown in Figure 11. 

   A frame is an area of the display screen that represents a component. 
   Frames are normally rectangular, but they need not be. 

   Like icons, frames can do the following: 

   °   Provide a handle onto parts, allowing parts to be manipulated as a 
       whole 

   °   Be dragged on the desktop and between windows 

   °   Be the target for drops during drag operations 

   °   Be opened into windows and closed back into frames 

   °   Be closed into icons and reopened back into frames 


   Unlike an icon, however, a frame allows a part's contents to be seen and 
   edited. 

   Frames show how a document is composed of embedded parts. 

   Frames allow a part's content to be edited in place, without requiring the 
   user to open separate windows.  In addition, there may be many frames 
   showing the content of a single part. 

   For example, when editing a 3D drawing, the user may wish to see a top 
   view, side view, face-on view, and wire-frame view.  Or, a part might 
   provide a graphical and tabular view of its contents.  Or, the header on a 
   page layout part might be showing the same part on each page of a 
   document.  Any change the user makes in one frame is immediately reflected 
   in all other visible frames on the same part.  Because different kinds of 
   parts have different requirements for passing changes to all frames, 
   OpenDoc provides the capability but does not specify the interface. 

   Frames (like icons) can be opened into windows.  Such windows are 
   transitory views; that means they are not permanent representations of 
   components, while frames are persistent.  When a frame is opened into a 
   window, the frame remains visible in its place.  Because frames already 
   show the contents of parts, one might ask why one would open a frame into 
   a window.  The answer is that some parts contain more content than can be 
   displayed in their frames. For example, a spreadsheet part may be quite 
   large, with only a portion of it appearing in a particular frame.  Opening 
   it into a window allows the entire spreadsheet to be seen and edited and 
   allows the user to adjust which portion will appear in the frame. 

   The preferred representation of contained parts is a property of the 
   container.  Some parts, such as folders, prefer to show embedded parts as 
   icons.  Others, such as text documents, prefer to show them as frames. 
   When a part is copied from a Desktop folder to an OpenDoc document, the 
   copied part changes its representation from an icon to a frame.  On the 
   other hand, when a part is copied from an OpenDoc document to a desktop 
   folder, the copied part changes its representation from a frame to an 
   icon.  In either case, the contents or properties of the copied part do 
   not change, but once inside a container, a part's representations may be 
   specified on a part-by-part basis. 

   The containing part tracks all frames directly embedded within it.  An 
   embedded part is logically contained in its containing part, just as its 
   frame is visually embedded in the containing part's frame.  A containing 
   part treats its embedded frames as regular elements of its own content. 
   It can move, select, delete, or otherwise manipulate them, without regard 
   to what they display and what data kind they are.  The embedded part 
   itself, however, takes care of drawing its contents and event handling 
   within an embedded frame. 

   The components must render themselves within their frame shape. 

   Those frames may have any shape, for example, square, uneven linear or any 
   other shape.  The frames may even overlay each other.  The actual 
   rendering is done by using facets.  The facets represent the actual 
   drawing surface associated with a components frame.  They simplify the 
   determination of the drawing location and the event dispatching.  Facets 
   are only needed when a frame becomes visible. 


 


                                              



 
   Figure 11. OpenDoc Frames and Facets 



   If a part is dragged into another part, frame negotiations take place as 
   shown in Figure 12. The embedded component in this example is indicated by 
   the black solid pattern.  The required space of the dragged part may 
   exceed the page limit or may be in conflict with the layout of the 
   containing part, so both have to agree on a common layout.  The containing 
   component has the last decision.  OpenDoc enables these negotiations by 
   providing a common interface. 



 


                                              



 
   Figure 12. OpenDoc Frame Negotiation 

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