tixDisplayStyle(n)

✨ tixDisplayStyle ✨

okay bestie, this is tixDisplayStyle(n) from the Tix Built-In Commands corner of the universe, and it's literally the blueprint for making Tix display items look cute and consistent without duplicating everything a million times. 💅

---

🌸 NAME 🌸

tixDisplayStyle — create a style object for Tix display items. No cap. 🎀

---

🦋 SYNOPSIS 🦋

tixDisplayStyle itemType ?-stylename name? ?-refwindow pathName?
?options value ...?

---

💖 DESCRIPTION 💖

The Tix Display Items mechanism was devised to solve a general problem: many Tix widgets — both existing and planned ones — display many items of many types simultaneously. It's giving "one system, many vibes." ✨

For example, a hierarchical listbox widget (HList) can display items of images, plain text and subwindows in the form of a hierarchy. Another widget, the tabular listbox (TList, currently planned and will be released in Tix 4.1) also displays items of the same types, although it arranges the items in a tabular form. Yet another widget, the spreadsheet widget, also displays similar types of items, but in yet another format. The range, honestly, is iconic. 🌈

In these examples, the display items in different widgets are only different in how they are arranged by the host widget. In Tix, display items are clearly separated from the host widgets. The advantage is twofold: first, the creation and configuration of display items become uniform across different host widgets. Second, new display item types can be added without needing to modify the existing host widgets. Efficiency? Slay. 💖

In a way, Tix display items are similar to the items inside the Tk canvas widget. However, unlike the Tix display items, the canvas items are not independent of the canvas widget; this makes it impossible to use the canvas items inside other types of TK widgets. So Tix said "actually, let's make them independent," and that's the tea. 🍓

The appearance of a display item is controlled by a set of attributes. It is observed that each of the attributes usually falls into one of two categories: "individual" or "collective". For example, the text items inside an HList widget may all display a different text string; however, in most cases, the text items share the same color, font and spacing. Instead of keeping a duplicated version of the same attributes inside each display item, it will be advantageous to put the collective attributes in a special object called a display style.

First, there's the space concern: a host widget may have many thousands of items, and keeping duplicated attributes will be very wasteful. Second, when it becomes necessary to change a collective attribute — like changing all the text items' foreground color to red — it will be more efficient to change only the display style object than to modify all the text items one by one. That's the whole point, bestie. 💅

The attributes of a display item are thus stored in two places: it has a set of item options to store its individual attributes. Each display item is also associated with a display style, which specifies the collective attributes of all items associated with itself.

The division between the individual and collective attributes is fixed and cannot be changed. Thus, when it becomes necessary for some items to differ in their collective attributes, two or more display styles can be used. For example, suppose you want to display two columns of text items inside an HList widget, one column in red and the other in blue. You can create a TextStyle object called "red", which defines a red foreground, and another called "blue", which defines a blue foreground. You can then associate all text items of the first column to "red" and the second column to "blue". Obsessed with the organization. 👑

---

🌈 DISPLAY ITEM TYPES AND OPTIONS 🌈

Currently there are four types of display items: text, image, imagetext and window. (TODO: need to document the "image" item)

---

🎀 IMAGETEXT ITEMS 🎀

Display items of the type imagetext are used to display an image together with a text string. Imagetext items support the following options:

ITEM OPTIONS

• -bitmap bitmap — specifies the bitmap to display in the item.
• -image image — specifies the image to display in the item. When both the -bitmap and -image options are specified, only the image will be displayed.
• -style imageTextStyle — specifies the display style to use for this item. Must be the name of an imagetext display style that has already be created by the tixDisplayStyle(n) command.
• -showimage showImage — a Boolean value that specifies whether the image/bitmap should be displayed.
• -showtext showText — a Boolean value that specifies whether the text string should be displayed.
• -text text — specifies the text string to display in the item.
• -underline underline — specifies the integer index of a character to underline in the text string in the item. 0 corresponds to the first character of the text displayed in the widget, 1 to the next character, and so on.

STYLE OPTIONS

The style information of imagetext items is stored in the imagetext display style. The following options are supported:

STANDARD OPTIONS

• activeBackground — standard option, details in options(n).
• activeForeground — standard option, details in options(n).
• anchor — standard option, details in options(n).
• background — standard option, details in options(n).
• disabledBackground — standard option, details in options(n).
• disabledForeground — standard option, details in options(n).
• foreground — standard option, details in options(n).
• font — standard option, details in options(n).
• justify — standard option, details in options(n).
• padX — standard option, details in options(n).
• padY — standard option, details in options(n).
• selectBackground — standard option, details in options(n).
• selectForeground — standard option, details in options(n).
• wrapLength — standard option, details in options(n).

See the options(n) manual entry for details on the standard options.

STYLE-SPECIFIC OPTIONS

• Name: gap
• Class: Gap
• Switch: -gap

Specifies the distance between the bitmap/image and the text string, in number of pixels. Cute spacing moment. 🎀

---

🌸 TEXT ITEMS 🌸

Display items of the type text are used to display a text string in a widget. Text items support the following options:

ITEM OPTIONS

• -style textStyle — specifies the display style to use for this text item. Must be the name of a text display style that has already be created by the tixDisplayStyle(n) command.
• -text text — specifies the text string to display in the item.
• -underline underline — specifies the integer index of a character to underline in the item. 0 corresponds to the first character of the text displayed in the widget, 1 to the next character, and so on.

STYLE OPTIONS

STANDARD OPTIONS

• activeBackground — standard option, details in options(n).
• activeForeground — standard option, details in options(n).
• anchor — standard option, details in options(n).
• background — standard option, details in options(n).
• disabledBackground — standard option, details in options(n).
• disabledForeground — standard option, details in options(n).
• foreground — standard option, details in options(n).
• font — standard option, details in options(n).
• justify — standard option, details in options(n).
• padX — standard option, details in options(n).
• padY — standard option, details in options(n).
• selectBackground — standard option, details in options(n).
• selectForeground — standard option, details in options(n).
• wrapLength — standard option, details in options(n).

See the options(n) manual entry for details on the standard options. 💖

---

🦋 WINDOW ITEMS 🦋

Display items of the type window are used to display a sub-window in a widget. Window items support the following options:

ITEM OPTIONS

• -style windowStyle — specifies the display style to use for this window item. Must be the name of a window display style that has already be created by the tixDisplayStyle(n) command.
• Name: window
• Class: Window
• Switch: -window
• Alias: -widget

Specifies the sub-window to display in the item.

STYLE OPTIONS

STANDARD OPTIONS

• anchor — standard option, details in options(n).
• padX — standard option, details in options(n).
• padY — standard option, details in options(n).

See the options(n) manual entry for details on the standard options. ✨

---

🧚 CREATING DISPLAY ITEMS 🧚

Display items do not exist on their own and thus they cannot be created independently of the widgets they reside in. As a rule, display items are created by special widget commands of their "host" widgets. For example, the HList widgets has a command item which can be used to create new display items. The following code creates a new imagetext item at the third column of the entry foo inside an HList widget:

tixHList .h -columns 3
.h add foo
.h item create foo 2 -itemtype imagetext -text Hello -image image1

The item create command of the HList widget accepts a variable number of arguments. The special argument -itemtype specifies which type of display item to create. Options that are valid for this type of display items can then be specified by one or more option-value pairs. Very "choose your own adventure," but make it Tix. 🦋

After the display item is created, they can then be configured or destroyed using the commands provided by the host widget. For example, the HList widget has the command item configure, item cget and item delete for accessing the display items.

---

👑 CREATING AND MANIPULATING DISPLAY STYLES 👑

Display styles are created by the command tixDisplayStyle:

itemType must be one of the existing display items types such as text, imagetext, window or any new types added by the user. Additional arguments can be given in one or more option-value pairs. option can be any of the valid option for this display style or any of the following:

• -stylename name — specifies a name for this style. If unspecified, then a default name will be chosen for this style.
• -refwindow pathName — specifies a window to use for determine the default values of the display type. If unspecified, the main window will be used. Default values for the display types can be set via the options database.

The following example sets the -disablebackground and -disabledforeground options of a text display style via the option database:

option add *table.list*disabledForeground blue
option add *table.list*disabledBackground darkgray
tixDisplayStyle text -refwindow .table.list -fg red

By using the option database to set the options of the display styles, we can avoid hard-coding the option values and give the user more flexibility in customization. See option(n) for a detailed description of the option database. 💅

💅 STYLE COMMAND 💅

Okay so the tixDisplayStyle command creates a new Tcl command whose name is the same as the name of the newly created display style. That command may be used to invoke various operations on the display style. It has this general form:

styleName option ?arg arg ...?

styleName is the name of the command. option and the args determine the exact behavior of the command. The possible commands are giving main-character energy:

• styleName cget option — returns the current value of the configuration option given by option. option may have any of the valid options of this display style.
• styleName configure ?option? ?value option value ...? — query or modify the configuration options of the display style. If no option is specified, it returns a list describing all of the available options for styleName (see Tk_ConfigureInfo for information on the format of this list). If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified). If one or more option-value pairs are specified, then the command modifies the given option(s) to have the given value(s); in this case the command returns an empty string. option may have any of the valid options of this display style.
• styleName delete — destroy this display style object. Bye bestie 💅

---

🍓 EXAMPLE 🍓

The following example creates two columns of data in a HList widget. The first column is in red and the second column in blue. The colors of the columns are controlled by two different text styles. Also, the anchor and font of the second column is chosen so that the income data is aligned properly.

set courier {courier 14}
set h [tixHList .h -columns 2]; pack $h
set red  [tixDisplayStyle text -fg #800000]
set blue [tixDisplayStyle text -fg #000080 \
          -anchor e -font $courier]

foreach n {{Joe $10,000} {Peter $20,000} {Raj $90,000}} {
    set entry [$h addchild {}]
    $h item create $entry 0 -itemtype text \
  -text [lindex $n 0] -style $red
    $h item create $entry 1 -itemtype text \
  -text [lindex $n 1] -style $blue
}

---

🔑 KEYWORDS 🔑

• display item
• display style
• imagetext

---

That’s the footer vibe, bestie: Tix 8.0 and tixDisplayStyle(n) — signed off with sparkles and absolutely no cap 💖✨🎀