[pedevel] 2nd. Suggestion for refactoring of PText
- From: Oliver Tappe <pedevel@xxxxxxxxxxxxxxx>
- To: Pe Develop <pedevel@xxxxxxxxxxxxx>
- Date: Sat, 12 Apr 2008 18:38:59 +0200
Hi again,
here's my next suggestion:
A - The Basic Text Model
CTextBuffer (was: PTextBuffer)
- exists once per file
- implements a gap-in-the-middle buffer abstraction (allowing swift
consecutive insertions at the same place)
- supports inserting and deleting text
- manages a set of listeners and a queue of changes for each listener
- listeners will be informed asynchronously by BMessage when their queue
becomes non-empty
B - Specific Functionality Models (Controlling the Basic Text Model)
CTextEditor
- creates connection between CTextBuffer and itself
- listens to CTextBuffer, i.e. receives ModelChanged-Messages and polls
the actual changes from its own queue in the model
- implements basic editing (insert & delete)
- implements language-specific formatting (auto-indenting,
brace-matching)
- sets up CTextStructure, CTextSelection and CTextSearch
- is linked to a single view (CView - see below)
- provides complete and clean interface (facade) to be used by
PTextView and potential scripting language - many methods of this
interface are implemented by either CTextStructure, CTextSelection or
CTextSearch
Examples for methods implemented here:
+ InsertText()
+ DeleteText()
+ FindMatching()
+ AutoIndent()
CTextStructure
- refers to a CTextBuffer and analyses the contents of that
- implements structural analysis of text:
+ maintains info about individual (logical) lines, i.e. wrapping
happens here
+ supports finding word boundaries (via callout to
language-addon)
+ supports finding logical blocks (functions) - delegating the
real
work to a language-addon
Examples for methods implemented here:
+ Offset2Line()
+ Line2Offset()
+ SetWrapColumn()
+ SetWrappingEnabled()
CTextSelection
- refers to a CTextBuffer
- refers to a CTextStructure
- maintains current position (caret) and start of selection (anchor)
- maintains virtual position in line (column of caret before vertical
movement started)
- supports navigation along structural items (chars, lines, words,
functions)
- supports selecting along structural items
- supports block selection
Examples for methods implemented here:
+ GoToLine()
+ GoToOffset()
+ MoveCharacterLeft()
+ MoveCharacterRight()
+ MoveLineUp()
+ MoveLineDown()
+ SetSelection()
+ GetSelection()
+ GetSelectedText()
+ ExtendSelectionCharacterLeft()
+ ExtendSelectionCharacterRight()
CTextSearch
- refers to a CTextBuffer
- executes searches and manages results and replace-states
- implements replacing (as delete + insert)
Examples for methods implemented here:
+ StartSearch()
+ SearchNext()
+ GetCurrentMatch()
+ CanReplace()
+ Replace()
C - Views
CView [abstract class]
- declares DirtyLinesChanged() which is invoked by CTextEditor whenever
something has changed that made one or more lines dirty.
PEditView (was: PText)
- is a CView
- implements DirtyLinesChanged() to invoke RedrawDirtyLines().
- uses CTextEditor to implement the edit view
- translates key/mouse events to appropriate method calls on CTextEditor
- renders text for editing on screen
PPrintView
- is a CView
- probably provides empty DirtyLinesChanged() [only redraws once upon
creation?]
- sets up CTextEditor as appropriate for printing (activates wrapping)
- renders text for printing (less color, hidden invisibles)
Well, that's it for this time ;-)
Again, please do not hesitate to send comments.
cheers,
Oliver
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