cappuccino/Tests/Manual/TextEditor/WORKLIST.md

TextEditor Work List

TextEditor is a document-based test application and a tutorial. When the app uses AppKit, it shows gaps in the framework. This list records those gaps and the planned additions to the app.

AppKit gaps

Windows and documents

• The "save changes" alert is modal for the whole app. CPDocument shows it with runModal (CPDocument.j:903). Cocoa attaches it as a sheet to the document window, so that only that document is blocked.
• Save cannot work without a server. With no file URL, Save uses CPSavePanel, which falls back to window.prompt (CPSavePanel.j:79). CPDocument then sends an HTTP POST. A storage facade is needed, with local (IndexedDB) and remote (HTTP) implementations.

Clipboard

• Paste and Cut from the Edit menu do nothing. -[CPTextView paste:] (CPTextView.j:521) and cut: (:1754) return unless the current event is CPAppKitDefined. Only the browser's native clipboard events, from the keyboard, create that event.
• Copy from the Edit menu cannot reach the system clipboard. It fills only the internal CPPasteboard.
• Fix: when a menu item calls these methods, use the asynchronous Clipboard API (navigator.clipboard). Read RTF first, then plain text. Write plain text, and RTF where the browser allows it. Keep the keyboard path unchanged.

Toolbar

• The Fonts and Print standard items are not implemented. _standardItemWithItemIdentifier: returns nil for both (_CPToolbarItem.j:641). AppKit needs _CPToolbarShowFontsItem (sends orderFrontFontPanel:) and _CPToolbarPrintItem (sends printDocument:). nib2cib needs matching classes.

Text features not yet supported

• Images in text. AppKit has no general CPTextAttachment class, only the table attachment _CPTableTextAttachment. The RTF parser and producer do not handle \pict.
• Lists. There is no CPTextList, and CPParagraphStyle has no textLists.

Text view

How the text system works, for the entries below: CPTextView does not use CSS text layout. CPSimpleTypesetter measures text with the canvas measureText (sizeWithFont:inWidth: in CPStringDrawing.j), measuring growing substrings so that each character's advancement includes the browser's kerning. It then breaks lines, places tabs, and applies indents and alignment itself (CPTypesetter.j). _CPLineFragment (CPLayoutManager.j) draws each run of identical attributes as one absolutely positioned <span>, at the computed position, with white-space: pre and the run's font, colour and underline in CSS. Inside a span the browser shapes the glyphs, including its own kerning and ligatures.

• Kerning and ligature settings are not implemented. Format > Font > Kern sends useStandardKerning:, turnOffKerning:, tightenKerning: and loosenKerning:, and Format > Font > Ligatures sends useStandardLigatures:, turnOffLigatures: and useAllLigatures:. CPTextView implements none of them, so the items are disabled. CPText.j defines CPKernAttributeName and CPLigatureAttributeName, but only the RTF producer reads them. A complete implementation needs: the seven actions, changing the attributes over the selection or the typing attributes with undo, as the baseline actions do; the typesetter adding a run's CPKernAttributeName value to each character's advancement, and measuring with the same ligature setting it draws with; and _CPLineFragment setting CSS letter-spacing and font-variant-ligatures on each run's span to match.
• The font panel needs polish. Found during the Format menu review on 24 October: the panel works with the text view, but its appearance and behaviour need refinement. The specific problems are not yet recorded; list them here, compared with the native font panel, when the panel is reviewed. CPFontPanel is in AppKit/CPTextView/CPFontPanel.j.

Ruler

• Marker appearance and vertical alignment differ from TextEdit. The marker images, and where markers sit across the ruler, are interim until Aristo3 supplies its own; adjust them to match TextEdit then. A tab stop dragged up off the ruler follows the pointer and is clipped by the ruler's edge, as in TextEdit. Dragged down off the ruler, it stays on its line and is drawn faded until release; TextEdit's behaviour in that direction has not been checked.

nib2cib

• nib2cib ignores the ruler settings. The "Uses Ruler" setting in Interface Builder does not reach the cib. CPTextView and CPRulerView also need to archive their ruler settings.
• The content view's resizing setting does not reach the cib. Making the document window's content view resize with the window in DocumentWindow.xib produces a byte-identical DocumentWindow.cib. CPView omits the autoresizing mask from the archive only when it is CPViewNotSizable (CPView.j:4016), so the content view is archived as not sizable. Not yet determined whether ibtool or nib2cib drops the setting. The app still behaves correctly, because the window resizes its content view itself.

Menus and key equivalents (needs discussion)

• The key equivalent of a disabled menu item reaches the browser. -[CPMenu performKeyEquivalent:] (CPMenu.j:1059) stops the browser's default action only when the matching item is enabled. For a disabled item it reports the key as handled, but the browser still acts on it: with File > Close disabled, Cmd-W closes the browser tab. Cocoa consumes the key equivalent of a disabled item with a beep. Stopping the browser's default for disabled items as well would match Cocoa for most keys, but not all: some browsers do not let a page block certain shortcuts, such as Cmd-W, Cmd-N and Cmd-T in Chrome, and Copy, Cut and Paste must keep reaching the browser for its clipboard events. This needs careful thought, and perhaps discussion, before any change.

Platform

• Key equivalents on platforms other than macOS. Filed as an issue.

Opportunities for improvement

• Justification is nominally functional, but its quality is limited. CPSimpleTypesetter breaks lines greedily: it fills each line as far as it fits, as Cocoa does, and then spreads the spare width of each wrapped line evenly over that line's spaces. This naive algorithm does not and cannot produce the quality that modern typesetting expects. It decides each line alone, so word spacing varies widely from line to line, and loose lines are common. Quality needs paragraph-wide line breaking in the manner of Knuth-Plass, as Typst also uses, with language-aware hyphenation. Cappuccino measures and lays out text itself, so this belongs in the typesetter, as its only behaviour, with no setting for users or developers.

Planned additions to the app

• Fonts through CPFontManager and CPFontPanel.
• RTF reading and writing.
• Images and lists in text.
• A storage facade, with saving and opening in IndexedDB and through HTTP.
• An asynchronous fetch test: fetch the text of a page and show it for editing. The page must allow cross-origin requests.
• An inspector pane with CPSplitViewController and CPViewController, with a View menu item that sends toggleInspector:.
• Documents in separate browser windows with CPPlatformWindow.
• A Settings window. The first setting is the minimum size of document windows, now the constants DocumentWindowMinimumWidth and DocumentWindowMinimumHeight in DocumentWindowController.j.

Tests done

• One window for each document, each loaded from its own cib.
• Insert Lorem Ipsum through the responder chain.
• Undo and redo over several levels, separate for each document.
• Text colour through CPColorPanel.
• Paragraph indents through the ruler markers.
• The "save changes" alert when a document closes.
• A minimum size for document windows, through the window delegate. The window stops at the minimum while the pointer keeps moving, as in macOS, and it can still be moved and resized afterwards.
• View > Show Toolbar and Hide Toolbar: the item's title follows the toolbar's visibility.
• The Window menu lists the open document windows, marks the main window with a check mark and brings a window to the front when chosen. Bring All to Front can be tested once documents open in separate browser windows.
• The About panel shows the display name from CPBundleDisplayName.
• Edit > Allow Undo turns undo on and off for the active document. With undo off, Undo and Redo stay disabled, and the check mark follows the document in front.
• The ruler: markers follow the paragraph at the selection; first line, head and right indents change the layout as shown; clicking adds a tab stop, and dragging moves or removes one; the Control-click menu changes a tab stop's type; the ruler's zero lines up with the start of the text, and markers at 0 are fully visible.
• Text stays inside the visible width, with Cocoa's 5-point line fragment padding.
• Tab characters: the Tab key inserts a tab in the text view, and left, centre, right and decimal tab stops align their columns.
• Format > Text > Copy Ruler and Paste Ruler apply one paragraph's indents and tab stops to others.
• Format > Font > Baseline: superscript, subscript, raised and lowered baselines lay out correctly, and Use Default restores the text, for an exact or a wider selection.
• Format > Text > Justify: wrapped lines fill the width between the indents, with the spare width spread over the spaces; the last line of a paragraph stays left aligned. Centred text is centred between the indents, and spaces at the end of a wrapped line hang outside the alignment.
• Format > Font > Copy Style and Paste Style: the style of the first character of the selection is applied to the whole target selection, which keeps its paragraph style.
• Builds with both the legacy toolchain and capp-build.