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21.11. The Text Widget

Create a Text widget with the Text method:

$parentwidget->Text ( options)

The standard configuration options that apply to Text are: -background, -bg, -bor-derwidth, -bd, -cursor, -exportselection, -font, -foreground, -fg, -height, -high-lightbackground, -highlightcolor, -highlightthickness, -insertbackground, -in-sertborderwidth, -insertofftime, -insertontime, -insertwidth, -padx, -pady, -re-lief, -selectbackground, -selectborderwidth, -selectforeground, -state, -takefo-cus, -width, -xscrollcommand, and -yscrollcommand.

Other options are:

-setgrid => boolean
Turns on gridding for the Text widget. Default is 0 (off).

-spacing1 => amount
Defines the amount of space left on the top of a line of text that starts on its own line. Default is 0.

-spacing2 => amount
Defines the amount of space left on the top of a line of text after it has been automatically wrapped by the Text widget. Default is 0.

-spacing3 => amount
Defines the amount of space left after a line of text that has been ended by \n. Default is 0.

-tabs => list
Specifies a list of tab stops to use in the text widget. Default is undefined (no tab stops).

-wrap => mode
Sets the mode for determining automatic line wrapping. Values are none (no wrapping), char (wrap at any character), or word (wrap at a word boundary). Default is char.

21.11.2. Text Methods

In addition to configure and cget, the following methods are defined for the Text widget:

bbox
Returns the location and dimensions of the bounding box surrounding the character at the specified index. The returned list contains four numbers representing (respectively) the x coordinate of the upper-left corner, the y coordinate of the upper-left corner, the width of the text in pixels, and the height of the text in pixels.

compare
Performs a comparison on two indexes. For example:

if ($text->compare('insert', '==', 'end') { 
        # we're at the end of the text
}

The valid operators are <, <=, ==, >=, and !=.

debug
Given a Boolean, turns debugging on or off.

delete
Deletes text from the text widget. To delete everything:

$text->delete(0, 'end');
dlineinfo
Returns the location and dimensions of the bounding box surrounding the line at the specified index. The returned list contains five numbers representing (respectively) the x coordinate of the upper-left corner, the y coordinate of the upper-left corner, the width of the text in pixels, the height of the text in pixels, and the baseline position of the line.

get
Returns the text located in the given index range.

index
Given a named index, returns its numeric equivalent in the format line.char.

insert
Inserts text into the widget at the specified location. The second argument is the text to insert, and the third argument is either a single tag or a list reference containing the names of multiple tags to apply to the text. Subsequent arguments alternate between text and tags. For example:

$text->insert('end', 'You want to do ', 'normal', 
                     'what?!', ['bold','red']);
search
Returns the index containing a particular string in the Text widget. For example, to search backwards for a case-insensitive hostname starting from the end of the text:

$hostindex = $text->search(-nocase, -backwards, $hostname, 'end');

The search method takes several switches to modify the search, each starting with -. The first argument that does not start with - is taken to be the search string. The switches are:

-forwards
Searches forwards starting at the specified index.

-backwards
Searches backwards starting at the specified index.

-exact
Matches the string exactly (default).

-regexp
Treat the pattern as a regular expression.

-nocase
Ignores case.

-count => $variable
Stores the number of matches into the specified variable.

--
Interprets the next argument as the pattern. (Useful when the pattern starts with a -.)

see
Scrolls the text so that the portion of the text containing the specified index is visible.

window
Embeds widgets within the Text widget. The first argument can be any of: create, names, cget, and configure.

create
Inserts an embedded widget at a specified index. Each widget occupies one character in the Text widget. The widget must have already been created as a child of the Text widget. For example:

$button = $text->Label(-text => "How ya doing?");
$text->window('create','end', -window => $button);

Here, the -window option is used to identify the widget to embed. The list of options to window ('create') is:

-align
Determines the positioning within the line of text. Values are baseline, bottom, top, or center (default).

-padx
Adds padding in the x direction.

-pady
Adds padding in the y direction.

-window
Identifies the widget to embed.

names
Returns a list of widget types embedded into the Text widget.

cget
Returns information on the widget at the specified index:

$text->window('cget',0);
configure
Configures widget at the specified index:

$text->window('configure',0,-background => "green");
xview
Manipulates the text in view. With no arguments, returns a list of two numbers between 0 and 1, defining the portion of the text that is currently hidden on the left and right sides, respectively. With arguments, the function of xview changes:

index
If the first argument is an index, that position becomes the leftmost position in view.

moveto
Moves the specified fraction of the text to the left of the visible portion.

scroll
Scrolls the text left or right by the specified number of units (characters, in this context) or pages. Used primarily as a callback to a scrollbar; pressing on an arrow would move by units (characters), and pressing on the trough would move by pages. The number is either 1 or -1, to move forwards or backwards, respectively.

yview
Manipulates the text in view. With no arguments, returns a list of two numbers between 0 and 1, defining the portion of the text that is currently hidden on the top and bottom, respectively. With arguments, the function of yview changes:

index
If the first argument is an index, that position becomes the topmost position in view.

moveto
Moves the specified fraction of the text to the top of the visible portion.

scroll
Scrolls the text up or down by the specified number of units (lines, in this context) or pages. Used primarily as a callback to a scrollbar; pressing on an arrow would move by units (lines), and pressing on the trough would move by pages. The number is either 1 or -1, to move forwards or backwards, respectively.

21.11.3. Tags

You can associate a distinct set of format properties to a portion of the text using tags. A tag is defined with the tagConfigure method, and text is associated with a tag via an option to the insert or tagAdd method. For example:

$text->Text->pack;
$text->tagConfigure('bold', -font =>
     '-*-Courier-Medium-B-Normal-*-120-*-*-*-*-*-*');
$text->insert('end', "Normal text\n");
$text->insert('end', "Bold text\n", 'bold');

There are several methods defined for manipulating text tags:

tagAdd
Adds a tag to the text within the specified index range. For example, to assign the bold tag defined above to the current selection:

$text->tagAdd('bold','sel.first','sel.last');

You can supply multiple ranges as arguments to tagAdd.

tagBind
Executes a callback when a specified event happens on the tagged text. For example:

$text->tagBind('goto_end', "<Button-1>", sub {shift->see('end');} );
tagConfigure
Creates or changes settings for a text tag. For example:

$text->tagConfigure('link', -foreground => 'red');

Options for configuring text tags are:

-background => color
The color to use behind the text.

-bgstipple => bitmap
A pattern to draw behind the text.

-borderwidth => amount
The width of the edge drawn around the text.

-fgstipple => bitmap
A pattern used to draw the text.

-font => fontname
The font used for the text.

-foreground => color
The color of the text.

-justify => position
The justification of the text (any of left, right, and center). The default is left.

-lmargin1 => amount
The indentation for the first line of a paragraph.

-lmargin2 => amount
The indentation for subsequent lines of a paragraph (for hanging indents).

-offset => amount
The amount the text is raised or lowered from the baseline (for subscripts and superscripts).

-overstrike => boolean
Draws the text with a line through it.

-relief => type
The types of edges drawn around the text. Values for type can be flat, groove, raised, ridge, and sunken. Default is flat.

-rmargin => amount
The right margin.

-spacing1 => amount
The amount of space left on the top of a line of text that starts on its own line.

-spacing2 => amount
The amount of space left on the top of a line of text after it has been automatically wrapped by the Text widget.

-spacing3 => amount
The amount of space left after a line of text ended by \n.

-tabs => list
A list of tab stops to use in the Text widget.

-underline => boolean
Whether to underline the text.

-wrap => mode
Sets the mode for determining automatic line wrapping. Values are none (no wrapping), char (wrap at any character), or word (wrap at a word boundary).

tagCget
Returns configuration settings for a tag.

tagDelete
Deletes the specified tag(s).

tagRemove
Removes the tags from the text in the specified index range. (The tag itself remains defined, but is no longer applied to that text.)

tagRaise
Increases priority for a specified tag. With only one argument, the tag takes highest priority over all others; with a second argument of another tag, the tag's priority is just higher than the second tag. For example:

$text->tagRaise('bold','italic');
tagLower
Decreases priority for a specified tag. With only one argument, the tag takes lowest priority to all others; with a second argument of another tag, the tag's priority is just lower than the second tag. For example:

$text->tagLower('italic','bold');
tagNames
Returns the names of all tags applying to the specified index. With no index specified, returns all tags defined for the Text widget, regardless of whether they have been applied. For example:

@defined_tags = $text->tagNames;
tagRanges
Returns a list of index ranges to which the specified tag is defined. The returned list contains pairs of starting and ending indexes for the ranges. For example:

@bold_indexes = $text->tagRanges('bold');
tagNextrange
Given a tag name and an index, returns the next index range to which the specified tag is defined. For example:

@next_bold = $text->tagRanges('bold', 'insert');


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