wxTextCtrl - Functions for wxTextCtrl class
Please see following description for synopsis
wxTextCtrl(3) Erlang Module Definition wxTextCtrl(3)
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 con-
trols 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 differ-
ences 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 setSe-
lection/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 coordi-
nates 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 char-
acters and not the characters themselves. Thus, position 0 is the one
before the very first character in the control and so is a valid posi-
tion even when the control is empty. And if the control contains a sin-
gle character, it has two valid positions: 0 before this character and
1 - after it. This, when the documentation of various functions men-
tions "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 actu-
ally 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 func-
tion 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, com-
mand_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 horizon-
tal 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 other-
wise 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 posi-
tion 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 posi-
tion, 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 con-
trol.
getLineLength(This, LineNo) -> integer()
Types:
This = wxTextCtrl()
LineNo = integer()
Gets the length of the specified line, not including any trail-
ing 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 recom-
mended 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 get-
Value/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 getStringSe-
lection/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 plat-
form).
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 sep-
arated 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 setEd-
itable/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 oth-
erwise.
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 plat-
form).
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 getLast-
Position/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 plat-
form).
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 charac-
ters allowed, and they will cause appropriate line breaks. See
operator<<() and appendText/2 for more convenient ways of writ-
ing 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 setInsertionPoin-
tEnd/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 posi-
tion.
Return: The position value, or -1 if x or y was invalid.
wxWidgets team. wx 2.1.1 wxTextCtrl(3)