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NAME
wxTextCtrl - Functions for wxTextCtrl class
DESCRIPTION
A text control allows text to be displayed and edited.
It may be single line or multi-line. Notice that a lot of methods of the text controls are
found in the base wxTextEntry (not implemented in wx) class which is a common base class
for wxTextCtrl and other controls using a single line text entry field (e.g. wxComboBox).
Styles
This class supports the following styles:
wxTextCtrl Text Format
The multiline text controls always store the text as a sequence of lines separated by '\n'
characters, i.e. in the Unix text format even on non-Unix platforms. This allows the user
code to ignore the differences between the platforms but at a price: the indices in the
control such as those returned by getInsertionPoint/1 or getSelection/1 can not be used as
indices into the string returned by getValue/1 as they're going to be slightly off for
platforms using "\\r\\n" as separator (as Windows does).
Instead, if you need to obtain a substring between the 2 indices obtained from the control
with the help of the functions mentioned above, you should use getRange/3. And the indices
themselves can only be passed to other methods, for example setInsertionPoint/2 or
setSelection/3.
To summarize: never use the indices returned by (multiline) wxTextCtrl as indices into the
string it contains, but only as arguments to be passed back to the other wxTextCtrl
methods. This problem doesn't arise for single-line platforms however where the indices in
the control do correspond to the positions in the value string.
wxTextCtrl Positions and Coordinates
It is possible to use either linear positions, i.e. roughly (but not always exactly, as
explained in the previous section) the index of the character in the text contained in the
control or X-Y coordinates, i.e. column and line of the character when working with this
class and it provides the functions positionToXY/2 and xYToPosition/3 to convert between
the two.
Additionally, a position in the control can be converted to its coordinates in pixels
using PositionToCoords() (not implemented in wx) which can be useful to e.g. show a popup
menu near the given character. And, in the other direction, HitTest() (not implemented in
wx) can be used to find the character under, or near, the given pixel coordinates.
To be more precise, positions actually refer to the gaps between characters and not the
characters themselves. Thus, position 0 is the one before the very first character in the
control and so is a valid position even when the control is empty. And if the control
contains a single character, it has two valid positions: 0 before this character and 1 -
after it. This, when the documentation of various functions mentions "invalid position",
it doesn't consider the position just after the last character of the line to be invalid,
only the positions beyond that one (e.g. 2 and greater in the single character example)
are actually invalid.
wxTextCtrl Styles.
Multi-line text controls support styling, i.e. provide a possibility to set colours and
font for individual characters in it (note that under Windows wxTE_RICH style is required
for style support). To use the styles you can either call setDefaultStyle/2 before
inserting the text or call setStyle/4 later to change the style of the text already in the
control (the first solution is much more efficient).
In either case, if the style doesn't specify some of the attributes (for example you only
want to set the text colour but without changing the font nor the text background), the
values of the default style will be used for them. If there is no default style, the
attributes of the text control itself are used.
So the following code correctly describes what it does: the second call to
setDefaultStyle/2 doesn't change the text foreground colour (which stays red) while the
last one doesn't change the background colour (which stays grey):
wxTextCtrl and C++ Streams
This class multiply-inherits from std::streambuf (except for some really old compilers
using non-standard iostream library), allowing code such as the following:
Note that even if your build of wxWidgets doesn't support this (the symbol
wxHAS_TEXT_WINDOW_STREAM has value of 0 then) you can still use wxTextCtrl itself in a
stream-like manner:
However the possibility to create a std::ostream associated with wxTextCtrl may be useful
if you need to redirect the output of a function taking a std::ostream as parameter to a
text control.
Another commonly requested need is to redirect std::cout to the text control. This may be
done in the following way:
But wxWidgets provides a convenient class to make it even simpler so instead you may just
do
See wxStreamToTextRedirector (not implemented in wx) for more details.
Event Handling.
The following commands are processed by default event handlers in wxTextCtrl: wxID_CUT,
wxID_COPY, wxID_PASTE, wxID_UNDO, wxID_REDO. The associated UI update events are also
processed automatically, when the control has the focus.
See: create/4, wxValidator (not implemented in wx)
This class is derived (and can use functions) from: wxControl wxWindow wxEvtHandler
wxWidgets docs: wxTextCtrl
EVENTS
Event types emitted from this class: command_text_updated, command_text_enter, text_maxlen
DATA TYPES
wxTextCtrl() = wx:wx_object()
EXPORTS
new() -> wxTextCtrl()
Default ctor.
new(Parent, Id) -> wxTextCtrl()
Types:
Parent = wxWindow:wxWindow()
Id = integer()
new(Parent, Id, Options :: [Option]) -> wxTextCtrl()
Types:
Parent = wxWindow:wxWindow()
Id = integer()
Option =
{value, unicode:chardata()} |
{pos, {X :: integer(), Y :: integer()}} |
{size, {W :: integer(), H :: integer()}} |
{style, integer()} |
{validator, wx:wx_object()}
Constructor, creating and showing a text control.
Remark: The horizontal scrollbar (wxHSCROLL style flag) will only be created for
multi-line text controls. Without a horizontal scrollbar, text lines that don't fit
in the control's size will be wrapped (but no newline character is inserted).
Single line controls don't have a horizontal scrollbar, the text is automatically
scrolled so that the insertion point is always visible.
See: create/4, wxValidator (not implemented in wx)
destroy(This :: wxTextCtrl()) -> ok
Destructor, destroying the text control.
appendText(This, Text) -> ok
Types:
This = wxTextCtrl()
Text = unicode:chardata()
Appends the text to the end of the text control.
Remark: After the text is appended, the insertion point will be at the end of the
text control. If this behaviour is not desired, the programmer should use
getInsertionPoint/1 and setInsertionPoint/2.
See: writeText/2
canCopy(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if the selection can be copied to the clipboard.
canCut(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if the selection can be cut to the clipboard.
canPaste(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if the contents of the clipboard can be pasted into the text control.
On some platforms (Motif, GTK) this is an approximation and returns true if the
control is editable, false otherwise.
canRedo(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if there is a redo facility available and the last operation can be
redone.
canUndo(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if there is an undo facility available and the last operation can be
undone.
clear(This) -> ok
Types:
This = wxTextCtrl()
Clears the text in the control.
Note that this function will generate a wxEVT_TEXT event, i.e. its effect is
identical to calling SetValue("").
copy(This) -> ok
Types:
This = wxTextCtrl()
Copies the selected text to the clipboard.
create(This, Parent, Id) -> boolean()
Types:
This = wxTextCtrl()
Parent = wxWindow:wxWindow()
Id = integer()
create(This, Parent, Id, Options :: [Option]) -> boolean()
Types:
This = wxTextCtrl()
Parent = wxWindow:wxWindow()
Id = integer()
Option =
{value, unicode:chardata()} |
{pos, {X :: integer(), Y :: integer()}} |
{size, {W :: integer(), H :: integer()}} |
{style, integer()} |
{validator, wx:wx_object()}
Creates the text control for two-step construction.
This method should be called if the default constructor was used for the control
creation. Its parameters have the same meaning as for the non-default constructor.
cut(This) -> ok
Types:
This = wxTextCtrl()
Copies the selected text to the clipboard and removes it from the control.
discardEdits(This) -> ok
Types:
This = wxTextCtrl()
Resets the internal modified flag as if the current changes had been saved.
changeValue(This, Value) -> ok
Types:
This = wxTextCtrl()
Value = unicode:chardata()
Sets the new text control value.
It also marks the control as not-modified which means that IsModified() would
return false immediately after the call to changeValue/2.
The insertion point is set to the start of the control (i.e. position 0) by this
function.
This functions does not generate the wxEVT_TEXT event but otherwise is identical to
setValue/2.
See overview_events_prog for more information.
Since: 2.7.1
emulateKeyPress(This, Event) -> boolean()
Types:
This = wxTextCtrl()
Event = wxKeyEvent:wxKeyEvent()
This function inserts into the control the character which would have been inserted
if the given key event had occurred in the text control.
The event object should be the same as the one passed to EVT_KEY_DOWN handler
previously by wxWidgets. Please note that this function doesn't currently work
correctly for all keys under any platform but MSW.
Return: true if the event resulted in a change to the control, false otherwise.
getDefaultStyle(This) -> wxTextAttr:wxTextAttr()
Types:
This = wxTextCtrl()
Returns the style currently used for the new text.
See: setDefaultStyle/2
getInsertionPoint(This) -> integer()
Types:
This = wxTextCtrl()
Returns the insertion point, or cursor, position.
This is defined as the zero based index of the character position to the right of
the insertion point. For example, if the insertion point is at the end of the
single-line text control, it is equal to getLastPosition/1.
Notice that insertion position is, in general, different from the index of the
character the cursor position at in the string returned by getValue/1. While this
is always the case for the single line controls, multi-line controls can use two
characters "\\r\\n" as line separator (this is notably the case under MSW) meaning
that indices in the control and its string value are offset by 1 for every line.
Hence to correctly get the character at the current cursor position, taking into
account that there can be none if the cursor is at the end of the string, you could
do the following:
getLastPosition(This) -> integer()
Types:
This = wxTextCtrl()
Returns the zero based index of the last position in the text control, which is
equal to the number of characters in the control.
getLineLength(This, LineNo) -> integer()
Types:
This = wxTextCtrl()
LineNo = integer()
Gets the length of the specified line, not including any trailing newline
character(s).
Return: The length of the line, or -1 if lineNo was invalid.
getLineText(This, LineNo) -> unicode:charlist()
Types:
This = wxTextCtrl()
LineNo = integer()
Returns the contents of a given line in the text control, not including any
trailing newline character(s).
Return: The contents of the line.
getNumberOfLines(This) -> integer()
Types:
This = wxTextCtrl()
Returns the number of lines in the text control buffer.
The returned number is the number of logical lines, i.e. just the count of the
number of newline characters in the control + 1, for wxGTK and wxOSX/Cocoa ports
while it is the number of physical lines, i.e. the count of lines actually shown in
the control, in wxMSW. Because of this discrepancy, it is not recommended to use
this function.
Remark: Note that even empty text controls have one line (where the insertion point
is), so getNumberOfLines/1 never returns 0.
getRange(This, From, To) -> unicode:charlist()
Types:
This = wxTextCtrl()
From = To = integer()
Returns the string containing the text starting in the positions from and up to to
in the control.
The positions must have been returned by another wxTextCtrl method. Please note
that the positions in a multiline wxTextCtrl do not correspond to the indices in
the string returned by getValue/1 because of the different new line representations
(CR or CR LF) and so this method should be used to obtain the correct results
instead of extracting parts of the entire value. It may also be more efficient,
especially if the control contains a lot of data.
getSelection(This) -> {From :: integer(), To :: integer()}
Types:
This = wxTextCtrl()
Gets the current selection span.
If the returned values are equal, there was no selection. Please note that the
indices returned may be used with the other wxTextCtrl methods but don't
necessarily represent the correct indices into the string returned by getValue/1
for multiline controls under Windows (at least,) you should use
getStringSelection/1 to get the selected text.
getStringSelection(This) -> unicode:charlist()
Types:
This = wxTextCtrl()
Gets the text currently selected in the control.
If there is no selection, the returned string is empty.
getStyle(This, Position, Style) -> boolean()
Types:
This = wxTextCtrl()
Position = integer()
Style = wxTextAttr:wxTextAttr()
Returns the style at this position in the text control.
Not all platforms support this function.
Return: true on success, false if an error occurred (this may also mean that the
styles are not supported under this platform).
See: setStyle/4, wxTextAttr
getValue(This) -> unicode:charlist()
Types:
This = wxTextCtrl()
Gets the contents of the control.
Notice that for a multiline text control, the lines will be separated by (Unix-
style) \n characters, even under Windows where they are separated by a \r\n
sequence in the native control.
isEditable(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if the controls contents may be edited by user (note that it always
can be changed by the program).
In other words, this functions returns true if the control hasn't been put in read-
only mode by a previous call to setEditable/2.
isModified(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if the text has been modified by user.
Note that calling setValue/2 doesn't make the control modified.
See: markDirty/1
isMultiLine(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if this is a multi line edit control and false otherwise.
See: isSingleLine/1
isSingleLine(This) -> boolean()
Types:
This = wxTextCtrl()
Returns true if this is a single line edit control and false otherwise.
See: isSingleLine/1, isMultiLine/1
loadFile(This, Filename) -> boolean()
Types:
This = wxTextCtrl()
Filename = unicode:chardata()
loadFile(This, Filename, Options :: [Option]) -> boolean()
Types:
This = wxTextCtrl()
Filename = unicode:chardata()
Option = {fileType, integer()}
Loads and displays the named file, if it exists.
Return: true if successful, false otherwise.
markDirty(This) -> ok
Types:
This = wxTextCtrl()
Mark text as modified (dirty).
See: isModified/1
paste(This) -> ok
Types:
This = wxTextCtrl()
Pastes text from the clipboard to the text item.
positionToXY(This, Pos) -> Result
Types:
Result = {Res :: boolean(), X :: integer(), Y :: integer()}
This = wxTextCtrl()
Pos = integer()
Converts given position to a zero-based column, line number pair.
Return: true on success, false on failure (most likely due to a too large position
parameter).
See: xYToPosition/3
redo(This) -> ok
Types:
This = wxTextCtrl()
If there is a redo facility and the last operation can be redone, redoes the last
operation.
Does nothing if there is no redo facility.
remove(This, From, To) -> ok
Types:
This = wxTextCtrl()
From = To = integer()
Removes the text starting at the first given position up to (but not including) the
character at the last position.
This function puts the current insertion point position at to as a side effect.
replace(This, From, To, Value) -> ok
Types:
This = wxTextCtrl()
From = To = integer()
Value = unicode:chardata()
Replaces the text starting at the first position up to (but not including) the
character at the last position with the given text.
This function puts the current insertion point position at to as a side effect.
saveFile(This) -> boolean()
Types:
This = wxTextCtrl()
saveFile(This, Options :: [Option]) -> boolean()
Types:
This = wxTextCtrl()
Option = {file, unicode:chardata()} | {fileType, integer()}
Saves the contents of the control in a text file.
Return: true if the operation was successful, false otherwise.
setDefaultStyle(This, Style) -> boolean()
Types:
This = wxTextCtrl()
Style = wxTextAttr:wxTextAttr()
Changes the default style to use for the new text which is going to be added to the
control.
This applies both to the text added programmatically using writeText/2 or
appendText/2 and to the text entered by the user interactively.
If either of the font, foreground, or background colour is not set in style, the
values of the previous default style are used for them. If the previous default
style didn't set them neither, the global font or colours of the text control
itself are used as fall back.
However if the style parameter is the default wxTextAttr, then the default style is
just reset (instead of being combined with the new style which wouldn't change it
at all).
Return: true on success, false if an error occurred (this may also mean that the
styles are not supported under this platform).
See: getDefaultStyle/1
setEditable(This, Editable) -> ok
Types:
This = wxTextCtrl()
Editable = boolean()
Makes the text item editable or read-only, overriding the wxTE_READONLY flag.
See: isEditable/1
setInsertionPoint(This, Pos) -> ok
Types:
This = wxTextCtrl()
Pos = integer()
Sets the insertion point at the given position.
setInsertionPointEnd(This) -> ok
Types:
This = wxTextCtrl()
Sets the insertion point at the end of the text control.
This is equivalent to calling setInsertionPoint/2 with getLastPosition/1 argument.
setMaxLength(This, Len) -> ok
Types:
This = wxTextCtrl()
Len = integer()
This function sets the maximum number of characters the user can enter into the
control.
In other words, it allows limiting the text value length to len not counting the
terminating NUL character.
If len is 0, the previously set max length limit, if any, is discarded and the user
may enter as much text as the underlying native text control widget supports
(typically at least 32Kb). If the user tries to enter more characters into the text
control when it already is filled up to the maximal length, a wxEVT_TEXT_MAXLEN
event is sent to notify the program about it (giving it the possibility to show an
explanatory message, for example) and the extra input is discarded.
Note that in wxGTK this function may only be used with single line text controls.
setSelection(This, From, To) -> ok
Types:
This = wxTextCtrl()
From = To = integer()
Selects the text starting at the first position up to (but not including) the
character at the last position.
If both parameters are equal to -1 all text in the control is selected.
Notice that the insertion point will be moved to from by this function.
See: SelectAll() (not implemented in wx)
setStyle(This, Start, End, Style) -> boolean()
Types:
This = wxTextCtrl()
Start = End = integer()
Style = wxTextAttr:wxTextAttr()
Changes the style of the given range.
If any attribute within style is not set, the corresponding attribute from
getDefaultStyle/1 is used.
Return: true on success, false if an error occurred (this may also mean that the
styles are not supported under this platform).
See: getStyle/3, wxTextAttr
setValue(This, Value) -> ok
Types:
This = wxTextCtrl()
Value = unicode:chardata()
Sets the new text control value.
It also marks the control as not-modified which means that IsModified() would
return false immediately after the call to setValue/2.
The insertion point is set to the start of the control (i.e. position 0) by this
function unless the control value doesn't change at all, in which case the
insertion point is left at its original position.
Note that, unlike most other functions changing the controls values, this function
generates a wxEVT_TEXT event. To avoid this you can use changeValue/2 instead.
showPosition(This, Pos) -> ok
Types:
This = wxTextCtrl()
Pos = integer()
Makes the line containing the given position visible.
undo(This) -> ok
Types:
This = wxTextCtrl()
If there is an undo facility and the last operation can be undone, undoes the last
operation.
Does nothing if there is no undo facility.
writeText(This, Text) -> ok
Types:
This = wxTextCtrl()
Text = unicode:chardata()
Writes the text into the text control at the current insertion position.
Remark: Newlines in the text string are the only control characters allowed, and
they will cause appropriate line breaks. See operator<<() and appendText/2 for more
convenient ways of writing to the window. After the write operation, the insertion
point will be at the end of the inserted text, so subsequent write operations will
be appended. To append text after the user may have interacted with the control,
call setInsertionPointEnd/1 before writing.
xYToPosition(This, X, Y) -> integer()
Types:
This = wxTextCtrl()
X = Y = integer()
Converts the given zero based column and line number to a position.
Return: The position value, or -1 if x or y was invalid.