Another "paper cuts" weekend

[graemeg]

Hi everyone,

I like to call small and annoying bugs "paper cuts". I
collected a few and this weekend was time I got rid
of them - and then some!

Below is an update of recent changes in develop
branch. Some very nice rendering fixes, new
features in DocView, plenty of bug fixes in DocView etc.

fpGUI Development Summary

Commits 6d7d22d..3e9e24b (30 commits)

Overview

16 bug fixes
1 new feature
3 documentation updates
4 docview application improvements
3 refactoring / cleanup changes
2 rendering pipeline improvements
1 layout manager fix

Bug Fixes

• Docview rendering stopped prematurely leaving a blank area
  at the bottom. DrawRichTextLayout was using Widget.Height
  (preferred/intent size) instead of Widget.ActualHeight
  (real rendered size) to determine when to stop rendering
  lines.

• 4-bit BMP decoder: fixed row stride calculation for
  odd-width images. When width mod 8 == 1 (e.g. 9, 17, 25),
  the row padding was 4 bytes too short, causing diagonal
  shearing of OS/2 bitmap images displayed in docview.

• RichTextView CopyPlainTextToBuffer: output buffer was not
  null-terminated after stripping formatting tags, causing
  clipboard paste to include raw tag text such as
  from uninitialised memory.

• RichTextView scroll-to-top on click: MakeRowAndColumnVisible
  was being called for mouse clicks, scrolling the view
  unexpectedly. Mouse clicks target an already-visible
  position, so the scroll-into-view logic is now skipped for
  mouse-initiated cursor positioning.

• Scrollbar thumb not updating when position set
  programmatically. SetSBPosition now sets FRecalc before
  Invalidate, and RichTextView.Clear resets all scroll state
  so topic changes start from the top.

• Rich text content rendering over widget border during
  scrolling. Restored the border inset in GetTextAreaRect,
  matched to each BorderStyle.

• Treeview node text vertical centering on X11 canvas.
  Changed from GetAscent/2 to (GetAscent + GetDescent)/2
  for consistent centering across backends.

• AggCanvas GetHeight now returns ascent + descent (excluding
  FreeType line-leading) for consistency with the X11 backend.

• Treeview node layout: improved expand/collapse box rendering
  to prevent connector lines showing through, better row
  spacing, and corrected text centering.

• Always repaint all virtual children to keep the shared
  off-screen buffer complete in the alien-windows model.
  The old partial-child-repaint optimisation left areas as
  plain background after content-change paint cycles.

• Blit full buffer to screen after repainting all virtual
  children. Only blitting the dirty rect caused regions
  outside it to show stale content.

• Access violation fix due to render pipeline changes.

• Layout manager: no longer reduces developer-set
  MinWidth/MinHeight values. Only increases them when the
  layout's computed minimum exceeds the current value.

• MigLayout Grow shortcut was missing SetGrowWeight calls on
  both axes, causing widgets using .Grow to receive no extra
  space during layout.

• MigLayout PushX/PushY column growth: GetDefaultGrowWeights
  was reading component grow weights instead of push weights,
  preventing column-level growth from working.

• Docview: fixed missing encoding combobox after toolbar
  migration to MigLayout.

New Feature

• Text selection and copy in docview RichTextView. Users can
  now click and drag to select text in help topics, then copy
  to the clipboard via Ctrl+C, Ctrl+Insert, Ctrl+A (select
  all), or the right-click context menu. The underlying
  CopyPlainTextToBuffer was rewritten for UTF-8 support, and
  SetSelectionEndInternal/ClearSelection were fixed to use
  Repaint instead of direct Canvas access which caused access
  violations.

Documentation

• Updated virtual_window_architecture document for current
  paint and font models.

• Clarified GrowX vs PushX distinction in MigLayout quick
  start guide with code examples.

• Fixed asciidoc rendering warnings.

Rendering Pipeline

• Optimised rendering pipeline for the alien-windows
  (single OS window handle) model, replacing old per-widget
  OS window code with efficient in-memory buffer operations.

• Removed FInvalidRect dead code from TfpgWidget, as all
  virtual children are now unconditionally repainted.

Docview Application

• Revised toolbar layout after PushX support was implemented.

• More sensible minimum window sizes for better UX.

• Removed unnecessary property settings (were defaults).

• Removed ProfileEvent debug output calls.

Regards,

• Graeme -

[rchastain2]

Great job Graeme! Thank you very much for the "select and copy" feature.