package require ReadoutGUIAppLauncher
::ReadoutGUIAppLauncher name widget_name [nCols 1]
name destroy
name appendButton label commandString
name disableButton buttonName
name enableButton buttonName
name addViewToParentGUI [parent .]
The ReadoutGUIAppLauncher provides a convenient tool for adding buttons to a ReadoutGUI or any parent widget. The intention is to support users who want to add buttons on a ReadoutGUI that launch programs for configuring hardware in their DAQ. For example, one might have a Mesytec MCFD-16 in his/her system to configure. Rather than running the MCFD16Control program from the command line and having to remember all of the arguments to pass, a button could be added to launch the program the same way every time. Such an implementation makes it easier for people to use a system and also makes it more robust.
The ReadoutGUIAppLauncher is a snit::type, so usage of it follows all of the same semantics of other snit::types. Also, the ReadoutGUIAppLauncher that gets instantiated is not the actual widget to be displayed. Instead, the object is simply an interface to the widget it manages (a.k.a. the view) and handles all of the logic for it. This is written just so that you understand there is a difference at the most fundamental level between the ReadoutGUIAppLauncher and the widget displayed. However, it is best to treat the launcher object as though it were the view itself. The expectation is that you should need no direct access to the view.
The ReadoutGUIAppLauncher assumes that the parent widget its view is being added to has a layout managed by the grid algorithm. It will be DISASTROUS to use this class if the parent widget's layout is being managed by the pack algorithm. There is no problem if you are planning to use this with the ReadoutGUI, because that uses the grid algorithm.
Note that beginning with NSCLDAQ-V11.4-010, when the widget that contains the start buttons is destroyed all of the active subprocesses will be sent a SIGTERM signal asking them to exit. If you do not want your application to exit, you'll need to catch and handle the SIGTERM signal in your application. Normally, when used in ReadoutGUI it's perfectly ok for subprocesses started with this application to exit when the GUI exits.
Construct an instance of the ReadoutGUIAppLauncher snit::type. After invoking this
command, a new command ensemble will be created that begins with name.
The following items in this list of commands explain the various subcommands made available
in that newly created ensemble. This method will also create a new widget called
view_name that will be managed by the ReadoutGUIAppLauncher object.
The application launcher will be a set a buttons arranged as a grid in a frame. By default,
the number of columns in that grid will be 1, but the user can specify otherwise. The
nCols can be used to set the number of columns. Once this is
constructed, there is no support for changing the number of columns displayed.
The destructor should be called when the user is done with the object. It will destroy the view widget that it manages.
A new button will be appended to the view. Buttons are added in a left to right, top to bottom fashion. If the user intends to enable or disable the button that is created, he/she should use the value returned by this class to do so. The value returned by this class is the name of the newly created ttk::button.
Disabling the button is the same as setting the state of the button to disabled. The user
should use the value returned by the appendButton method to pass as the buttonName.
Enabling the button is the same as setting the state of the button to !disabled. The user
should use the value returned by the appendButton method to pass as the buttonName.
This effectively grids the view widgets to a parent. The placement of the view on the parent is fairly simple. It makes it span the full number of columns of the parent and then sets as a new row. A very important point to make is that this assumes the parent's layout is being managed by the grid algorithm. If that is not the case, DO NOT USE THIS!!
Example 1. Simple usage of the ReadoutGUIAppLauncher package
package require ReadoutGUIAppLauncher
# construct the launcher with a view called .launcher and 2 columns
ReadoutGUIAppLauncher launcher .launcher 2
# add 3 buttons
launcher appendButton "Launch Program0" "/path/to/program0 -option0 asdf"
launcher appendButton "Launch Program1" "/path/to/program1 -option0 asdf -bool-flag"
set btn2 [launcher appendButton "Launch Program2" "/path/to/program2"]
# grid the widget on the ReadoutGUI
launcher addViewToParentGUI
# disable the button for /path/to/program2
# by default, all buttons are enabled to start
launcher disableButton $btn2
# make sure the GUI updates before waiting 10 seconds
update
# wait 10 seconds before enabling it again
after 10000
# reenable the button for /path/to/program2
launcher enableButton $btn2