X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5f35b46aabdab414602d27bb92034c371bc09d2e..9c72cf7619064969b5c7f59cece74013789db4cf:/docs/latex/wx/richtextoverview.tex diff --git a/docs/latex/wx/richtextoverview.tex b/docs/latex/wx/richtextoverview.tex index e9a5116a6d..0242b4ff5e 100644 --- a/docs/latex/wx/richtextoverview.tex +++ b/docs/latex/wx/richtextoverview.tex @@ -10,7 +10,34 @@ Classes: \helpref{wxRichTextCtrl}{wxrichtextctrl}, \helpref{wxRichTextBuffer}{wx \helpref{wxRichTextFileHandler}{wxrichtextfilehandler}, \helpref{wxRichTextHTMLHandler}{wxrichtexthtmlhandler}, \helpref{wxRichTextXMLHandler}{wxrichtextxmlhandler} -wxRichTextCtrl provides a generic implementation of a rich text editor +wxRichTextCtrl provides a generic implementation of a rich text editor that can handle different character +styles, paragraph formatting, and images. It's aimed at editing 'natural' language text - if you need an editor that supports code editing, +wxStyledTextCtrl is a better choice. + +Despite its name, it cannot currently read or write RTF (rich text format) files. Instead, it +uses its own XML format, and can also read and write plain text. In future we expect to provide +RTF file capabilities. Custom file formats can be supported by creating additional +file handlers and registering them with the control. + +wxRichTextCtrl is largely compatible with the wxTextCtrl API, but extends it where necessary. +The control can be used where the native rich text capabilities of wxTextCtrl are not +adequate (this is particularly true on Windows) and where more direct access to +the content representation is required. It is difficult and inefficient to read +the style information in a wxTextCtrl, whereas this information is readily +available in wxRichTextCtrl. Since it's written in pure wxWidgets, any customizations +you make to wxRichTextCtrl will be reflected on all platforms. + +There are of course a few disadvantages to using wxRichTextCtrl. It is not native, +so does not behave exactly as a native wxTextCtrl, although common editing conventions +are followed. Users may miss the built-in spelling correction on Mac OS X, or any +special character input that may be provided by the native control. It would also +be a bad choice if intended users rely on screen readers that would be unhappy +with non-native text input implementation. You might mitigate this by providing +the choice between wxTextCtrl and wxRichTextCtrl, with fewer features in the +former case. + +wxRichTextCtrl does not yet support printing directly, but content can be converted +to HTML which can then be used with \helpref{wxHtmlEasyPrinting}{wxhtmleasyprinting}. The following screenshot shows the wxRichTextCtrl sample in action: @@ -18,17 +45,242 @@ $$\image{8cm;0cm}{richtextctrl.gif}$$ \wxheading{Example}\label{wxrichtextctrlexample} -TODO +The following code is taken from the sample, and adds text and styles to a rich text control programmatically. {\small \begin{verbatim} + wxRichTextCtrl* richTextCtrl = new wxRichTextCtrl(splitter, wxID_ANY, wxEmptyString, wxDefaultPosition, wxSize(200, 200), wxVSCROLL|wxHSCROLL|wxNO_BORDER|wxWANTS_CHARS); + + wxFont textFont = wxFont(12, wxROMAN, wxNORMAL, wxNORMAL); + wxFont boldFont = wxFont(12, wxROMAN, wxNORMAL, wxBOLD); + wxFont italicFont = wxFont(12, wxROMAN, wxITALIC, wxNORMAL); + + wxFont font(12, wxROMAN, wxNORMAL, wxNORMAL); + + m_richTextCtrl->SetFont(font); + + wxRichTextCtrl& r = richTextCtrl; + + r.BeginSuppressUndo(); + + r.BeginParagraphSpacing(0, 20); + + r.BeginAlignment(wxTEXT_ALIGNMENT_CENTRE); + r.BeginBold(); + + r.BeginFontSize(14); + r.WriteText(wxT("Welcome to wxRichTextCtrl, a wxWidgets control for editing and presenting styled text and images")); + r.EndFontSize(); + r.Newline(); + + r.BeginItalic(); + r.WriteText(wxT("by Julian Smart")); + r.EndItalic(); + + r.EndBold(); + + r.Newline(); + r.WriteImage(wxBitmap(zebra_xpm)); + + r.EndAlignment(); + + r.Newline(); + r.Newline(); + + r.WriteText(wxT("What can you do with this thing? ")); + r.WriteImage(wxBitmap(smiley_xpm)); + r.WriteText(wxT(" Well, you can change text ")); + + r.BeginTextColour(wxColour(255, 0, 0)); + r.WriteText(wxT("colour, like this red bit.")); + r.EndTextColour(); + + r.BeginTextColour(wxColour(0, 0, 255)); + r.WriteText(wxT(" And this blue bit.")); + r.EndTextColour(); + + r.WriteText(wxT(" Naturally you can make things ")); + r.BeginBold(); + r.WriteText(wxT("bold ")); + r.EndBold(); + r.BeginItalic(); + r.WriteText(wxT("or italic ")); + r.EndItalic(); + r.BeginUnderline(); + r.WriteText(wxT("or underlined.")); + r.EndUnderline(); + + r.BeginFontSize(14); + r.WriteText(wxT(" Different font sizes on the same line is allowed, too.")); + r.EndFontSize(); + + r.WriteText(wxT(" Next we'll show an indented paragraph.")); + + r.BeginLeftIndent(60); + r.Newline(); + + r.WriteText(wxT("Indented paragraph.")); + r.EndLeftIndent(); + + r.Newline(); + + r.WriteText(wxT("Next, we'll show a first-line indent, achieved using BeginLeftIndent(100, -40).")); + + r.BeginLeftIndent(100, -40); + r.Newline(); + + r.WriteText(wxT("It was in January, the most down-trodden month of an Edinburgh winter.")); + r.EndLeftIndent(); + + r.Newline(); + + r.WriteText(wxT("Numbered bullets are possible, again using subindents:")); + + r.BeginNumberedBullet(1, 100, 60); + r.Newline(); + + r.WriteText(wxT("This is my first item. Note that wxRichTextCtrl doesn't automatically do numbering, but this will be added later.")); + r.EndNumberedBullet(); + + r.BeginNumberedBullet(2, 100, 60); + r.Newline(); + + r.WriteText(wxT("This is my second item.")); + r.EndNumberedBullet(); + + r.Newline(); + + r.WriteText(wxT("The following paragraph is right-indented:")); + + r.BeginRightIndent(200); + r.Newline(); + + r.WriteText(wxT("It was in January, the most down-trodden month of an Edinburgh winter. An attractive woman came into the cafe, which is nothing remarkable.")); + r.EndRightIndent(); + + r.Newline(); + + wxArrayInt tabs; + tabs.Add(400); + tabs.Add(600); + tabs.Add(800); + tabs.Add(1000); + wxTextAttrEx attr; + attr.SetFlags(wxTEXT_ATTR_TABS); + attr.SetTabs(tabs); + r.SetDefaultStyle(attr); + + r.WriteText(wxT("This line contains tabs:\tFirst tab\tSecond tab\tThird tab")); + + r.Newline(); + r.WriteText(wxT("Other notable features of wxRichTextCtrl include:")); + + r.BeginSymbolBullet(wxT('*'), 100, 60); + r.Newline(); + r.WriteText(wxT("Compatibility with wxTextCtrl API")); + r.EndSymbolBullet(); + + r.WriteText(wxT("Note: this sample content was generated programmatically from within the MyFrame constructor in the demo. The images were loaded from inline XPMs. Enjoy wxRichTextCtrl!")); + + r.EndSuppressUndo(); \end{verbatim} } -\wxheading{Programming with wxRichTextCtrl} +\subsection{Programming with wxRichTextCtrl} + +You need to include {\tt } in your source, and link +with the appropriate wxWidgets library with {\tt richtext} suffix. Put the rich text +library first in your link line to avoid unresolved symbols. + +Then you can create a wxRichTextCtrl, with the wxWANT\_CHARS style if you want tabs to +be processed by the control rather than being used for navigation between controls. + +It's helpful to have a model of how styling works. Any piece of text can have its +style changed, but there also two global notions of style. The control's {\it basic} style +is the fundamental style for the whole control, to which other character and paragraph styles are +applied. For example, you can change the control's overall font by either calling SetBasicStyle with +the appropriate font style, or by calling SetFont. + +The {\it default} style, on the other hand, is applied to subsequently inserted +content. You might click on a Bold formatting tool, which sets bold as one of the default +attributes, and typing will appear in bold. Then when you select Italic, both +bold and italic attributes are applied as you type. The default attribute +is set with \helpref{SetDefaultStyle}{wxrichtextctrlsetdefaultstyle}. + +(To be finished.) + +\subsection{How wxRichTextCtrl is implemented} + +Data representation is handled by wxRichTextBuffer, and a wxRichTextCtrl +always has one such buffer. + +The content is represented by a hierarchy of objects, all derived from +wxRichTextObject. An object might be an image, a fragment of text, a paragraph, +or a whole buffer. Objects store a wxRichTextAttr containing style information; +although it contains both paragraph formatting and character style, the +paragraph style information is ignored by children of a paragraph (only +character style is relevant to these objects). + +The top of the hierarchy is the buffer, a kind of wxRichTextParagraphLayoutBox. +containing further wxRichTextParagraph objects, each of which can include text and +images. + +Each object maintains a range (start and end position) measured +from the start of the main parent box. + +When Layout is called on an object, it is given a size which the object +must limit itself to, or one or more flexible directions (vertical +or horizontal). So, for example, a centered paragraph is given the page +width to play with (minus any margins), but can extend indefinitely +in the vertical direction. The implementation of Layout caches the calculated +size and position. + +When the buffer is modified, a range is invalidated (marked as requiring +layout), so that only the minimum amount of layout is performed. + +A paragraph of pure text with the same style contains just one further +object, a wxRichTextPlainText object. When styling is applied to part of +this object, the object is decomposed into separate objects, one object +for each different character style. So each object within a paragraph always has +just one wxRichTextAttr object to denote its character style. Of course, this can +lead to fragmentation after a lot of edit operations, potentially leading +to several objects with the same style where just one would do. So +a Defragment function is called when updating the control's display, to ensure that +the minimum number of objects is used. + +(To be finished.) + +\subsection{wxRichTextCtrl roadmap} + +\wxheading{Bugs} + +This is an incomplete list of bugs. + +\begin{itemize} +\item Moving the caret up at the beginning of a line sometimes incorrectly positions the +caret. +\end{itemize} + +\wxheading{Features} -TODO +This is a list of some of the features that have yet to be implemented. Help with them will be appreciated. -\wxheading{How wxRichTextCtrl is implemented} +\begin{itemize} +\item Printing +\item RTF input and output +\item Floating images, with content wrapping around them +\item A ruler control +\item Standard editing toolbars +\item Automatic list numbering +\item Standard dialogs for paragraph/character formatting +\item Tables +\item Text frames +\item Add ability to show images in wxHTML output (currently uses +\item More complete stylesheet viewer, plus style sheet editing dialogs +\item Ability to store style sheets with documents +embedded images suitable only for browsers). +\end{itemize} -TODO +There are also things that could be done to take advantage of the underlying text capabilities of the platform; +higher-level text formatting APIs are available on some platforms, such as Mac OS X, and some of translation from +high level to low level wxDC API is unnecessary. However this would require additions to the wxWidgets API.