Defining Front Panel Controls

The user can create personal controls by dropping icons on the Install Icon controls.

While this provides easy customizability, the functionality it provides is a subset of the capabilities of Front Panel controls. For example, a control created using the Install Icon control cannot:

Provide animation
Display a client window
Change appearance when an event occurs (for example, upon receiving new mail)

This section describes how to manually create Front Panel controls.

For reference information on the syntax of Front Panel controls, see the dtfpfile(4X) man page.

Front Panel Control Definitions

The structure of a Front Panel control definition is:

CONTROL control_name
{
  TYPE            control_type
  CONTAINER_NAME  value
  CONTAINER_TYPE  value
  other fields defining appearance and behavior
}

Control Types

The TYPE field in the control definition specifies the basic behavior of the control.

Control TYPE	Control Behavior
icon	(Default) The control will run a specified action when the user clicks the control or drops a file on it.
blank	Placeholder used to adjust spacing of controls.
busy	Busy light. The control blinks (toggles images) when an action is invoked
client	A client window in the Front Panel.
clock	Clock.
date	Displays the current date.
file	Represents a file. Choosing the control runs the default action for the file.

To Create a New Control

This section describes the general steps for defining a control and describes how to create various types of controls.

If the control will have a PUSH_ACTION and/or DROP_ACTION, create the action definitions. These are the actions that run when the user clicks the control or drops a file on it.
Create the icon image files for the control.
For information about icon sizes, names, and locations, see “Icon Image Files”.
Create a new Front Panel configuration file in:
- System-wide: /etc/dt/appconfig/types/language/*.fp
- Personal: HomeDirectory/.dt/types/*.fp
Add the control definition to the file.
Save the file.
Choose Restart Workspace Manager from the Workspace menu.

Creating a Control that Runs an Action When Clicked

Use these fields to define the control's behavior:

TYPE: Set to icon
PUSH_ACTION: Specifies the name of the action to be run

For example, the following control, which will be put in the Personal Applications subpanel, runs a game the user has acquired:

CONTROL Ball
{
 TYPE            icon
 CONTAINER_NAME  PersAppsSubpanel
 CONTAINER_TYPE  SUBPANEL
 ICON            ball
 PUSH_ACTION     RunBallGame
 HELP_STRING     "Choose this control to play Ball."
}

The following control will be located in the upper left corner of the switch. It starts an action named CutDisp.

CONTROL StartCutDisp
{
  TYPE             icon
  CONTAINER_NAME   Switch
  CONTAINER_TYPE   SWITCH
  POSITION_HINTS   first
  ICON             cutdisp
  HELP_STRING      "Choose this control to run cutdisp."
  PUSH_ACTION      CutDisp
}

Creating a Control that Opens a File

Use these fields to define the control's behavior:

TYPE: Set to file
FILE_NAME: Specifies the path of the file to be opened
PUSH_ACTION: Set to Open

There must be an Open action defined for the data type of the file.

For example, the following control will be located on the far right side of the Main Panel. It starts Text Editor with the data file /users/ellen/PhoneList.txt. The Open action for *.txt files is part of the default action database.

CONTROL EditPhoneList
{
 TYPE            file
 FILE_NAME       /users/ellen/PhoneList.txt
 CONTAINER_NAME  Top
 CONTAINER_TYPE  BOX
 POSITION_HINTS  last
 ICON            PhoneBook
 HELP_STRING     "This control displays Ellen's phone list."
 PUSH_ACTION     Open
}

Creating a Control that Behaves as a Drop Zone

Use the DROP_ACTION field to specify the action that runs when the user drops a file on the control. The action must be capable of accepting a file argument.

Frequently, a control definition includes both a PUSH_ACTION and DROP_ACTION field. You can use the same action for the push and drop action.

For example, the following control, located in the Personal Applications subpanel, runs the X client xwud, which takes a file argument.

CONTROL Run_xwud
{
 CONTAINER_NAME   PerAppsSubpanel
 CONTAINER_TYPE   SUBPANEL
 POSITION_HINTS   2
 ICON             XwudImage
 PUSH_ACTION      RunXwud
 DROP_ACTION      RunXwud
}

Creating a Control that Monitors a File

Use these fields to define the control's behavior:

TYPE: Specify one of the following values:

icon	Use this type if you want to specify a `PUSH_ACTION` and/or `DROP_ACTION` for the control`.`
file	Use this type if you want the control, when chosen, to behave like the file when the file's icon is double-clicked in File Manager.

ICON and ALTERNATE_ICON:Describe the images used to indicate the non- changed and changed state of the monitored file.
MONITOR_TYPE: Describes the conditions causing the image to change. Use one of the following values:
mail
The control will change appearance when information is added to the file.
file
The control will change when the specified file becomes non- empty.
FILE_NAME: Specifies the file to be monitored.

For example, the following control looks for the presence of a file named meetings that you expect to be transferred to your system using anonymous ftp. The control is placed at the top of the Personal Applications subpanel.

CONTROL MonitorCalendar
{
 TYPE              file
 CONTAINER_NAME    PersonalApps
 CONTAINER_TYPE    SUBPANEL
 POSITION_HINTS    first
 FILE_NAME         /users/ftp/meetings
 MONITOR_TYPE      file
 ICON              meetingsno
 ALTERNATE_ICON    meetingsyes
}

Creating a One-Instance (Toggle) Control

A one-instance control checks to see whether the process started by the PUSH_ACTION is already running. If the process is not running, the PUSH_ACTION is run. If the process is already running, the window is moved to the top of the window stack in the current workspace.

Use these fields to define the control's behavior:

PUSH_RECALL: Set to True.
CLIENT_NAME: Specifies the name of the client to the control.
The value of CLIENT_NAME must match the first string (res_name) in the WM_CLASS property on the application's top-level window. For more information, see the xprop(1) man page.
PUSH_ACTION: Describes the action run when the user clicks the control.

For example, the following control runs one instance of an application whose action is named MyEditor.

CONTROL MyEditor
{
 TYPE            icon
 CONTAINER_NAME  Top
 CONTAINER_TYPE  BOX
 POSITION_HINTS  15
 PUSH_RECALL     True
 CLIENT_NAME     BestEditor
 PUSH_ACTION     StartMyEditor
 ICON            MyEd
}

To Create a Client Window Control

A client window control is an application window embedded in the Front Panel. For example, you can put a system load meter in the Front Panel by creating an xload client window control.

Define the control.
Use these fields to define the control's behavior:
- TYPE: Set to client.
- CLIENT_NAME: Specifies the client to be started.
  The value of CLIENT_NAME must match the first string (res_name) in the WM_CLASS properly on the application's top-level window. For more information, see the xprop(1) man page.
- CLIENT_GEOMETRY: Specifies the size, in pixels, needed for the client's Front Panel window.
  The xwininfo(1) man page describes how to find out the size of a window in pixels.
Choose Restart Workspace Manager from the Workspace menu.
Start the client from a terminal emulator command line.

For example, the following control displays a 30 X 20 pixel load meter.

CONTROL LoadMeter
{
 TYPE             client
 CONTAINER_NAME   Top
 CONTAINER_TYPE   BOX
 CLIENT_NAME      xload
 CLIENT_GEOMETRY  30x20
}

If the client is not saved and restored between sessions, you may want to configure the control to start the client when the user clicks it. For example, you can configure the LoadMeter control to start xload by adding the following line to the definition:

PUSH_ACTION StartXload

and creating the action:

ACTION StartXload
{
 WINDOW_TYPE    NO_STDIO
 EXEC_STRING    /usr/contrib/bin/X11/xload
}

To Animate a Control

You can attach an animation sequence to be used when the user chooses the control or drops an object on it.

In order to have an animation sequence, a control must:

Be type icon
Have a PUSH_ACTION or DROP_ACTION

Specify the animation sequence using the ANIMATION component:
ANIMATION animation_name { ANIMATION icon_image [delay] ANIMATION icon_image [delay] ... }
where delay is the time delay between animation icons, in milliseconds.
Add the PUSH_ANIMATION and/or DROP_ANIMATION fields to the control definition. The value is the name of the ANIMATION sequence.

For example, the following lines animate a control that starts the BestEditor application. The time delay between icons is 300 milliseconds. The example assumes you've created icon files frame1, frame2, etc.

CONTROL BestEditor
{
 ...
 PUSH_ANIMATION BestEdAnimation
 ...
}
 
ANIMATION BestEdAnimation
{
 ANIMATION frame1   300
 ANIMATION frame2
 ...
}

Providing On Item Help for Front Panel Controls

There are two ways to provide help for a control:

Providing a help string in the control definition.
The help string is displayed in the help viewer when the user invokes on- item help for the control. The help string cannot include formatting (such as headings) or links.
To provide a help string, specify the help string in the control definition:
HELP_STRING help_string
Specifying a help topic in a registered help volume.
A help topic is information authored using the full capabilities of the help system. Authoring a help topic requires you to use the desktop Help Developer's Kit.
To provide a help topic, specify the help volume and topic ID in the control definition:
HELP_VOLUME help_volume_name HELP_TOPIC topic_id

Defining Front Panel Controls

Technical documentation

» Table of Contents

» Index

Front Panel Control Definitions

Control Types

To Create a New Control

Creating a Control that Runs an Action When Clicked

Creating a Control that Opens a File

Creating a Control that Behaves as a Drop Zone

Creating a Control that Monitors a File

Creating a One-Instance (Toggle) Control

To Create a Client Window Control

To Animate a Control

Providing On Item Help for Front Panel Controls