A Source Code For The Task List Manager
A.1 A task list manager using menu gadgets
This section contains the complete source code to the first complete design of the task list manager, described in Chapters 3 to 5. To load this code into the environment, choose Tools > Open Example Project from any window in the environment. The code in this section can be loaded by choosing Task List 1 in the Documentation category of the Open Example Project dialog.
Contents of the file frame.dylan:
Module: task-list
Synopsis: Task List Manager.
Author: Harlequin Group plc
Copyright: (C) 1998, Harlequin Group plc. All rights reserved.
define constant $priority-items
= #(#("Low", #"low"),
#("Medium", #"medium"),
#("High", #"high"));
define frame <task-frame> (<simple-frame>)
slot frame-task-list :: <task-list> = make(<task-list>);
// definition of menu bar
pane task-menu-bar (frame)
make(<menu-bar>,
children: vector(frame.file-menu,
frame.edit-menu,
frame.task-menu,
frame.help-menu));
// definition of menus
pane file-menu (frame)
make(<menu>, label: "File",
children: vector(frame.open-menu-button,
frame.save-menu-button,
frame.save-as-menu-button,
frame.exit-menu-button));
pane edit-menu (frame)
make(<menu>, label: "Edit",
children: vector(frame.cut-menu-button,
frame.copy-menu-button,
frame.paste-menu-button));
pane task-menu (frame)
make(<menu>, label: "Task",
children: vector(frame.add-menu-button,
frame.remove-menu-button));
pane help-menu (frame)
make(<menu>, label: "Help",
children: vector(frame.about-menu-button));
// definition of menu buttons
// Commands in the File menu
pane open-menu-button (frame)
make(<menu-button>, label: "Open...",
activate-callback: open-file,
accelerator: make-keyboard-gesture(#"o", #"control"),
documentation: "Opens an existing file.");
pane save-menu-button (frame)
make(<menu-button>, label: "Save",
activate-callback: save-file,
accelerator: make-keyboard-gesture(#"s", #"control"),
documentation: "Saves the current file to disk.");
pane save-as-menu-button (frame)
make(<menu-button>, label: "Save As...",
activate-callback: save-as-file,
documentation:
"Saves the current file with a new name.");
pane exit-menu-button (frame)
make(<menu-button>, label: "Exit",
activate-callback: exit-task,
accelerator: make-keyboard-gesture(#"f4", #"alt"),
documentation: "Exits the application.");
//Commands in the Edit menu
pane cut-menu-button (frame)
make(<menu-button>, label: "Cut",
activate-callback: not-yet-implemented,
accelerator: make-keyboard-gesture(#"x", #"control"),
documentation: "Cut the selection to the clipboard.");
pane copy-menu-button (frame)
make(<menu-button>, label: "Copy",
activate-callback: not-yet-implemented,
accelerator: make-keyboard-gesture(#"c", #"control"),
documentation: "Copy the selection to the clipboard.");
pane paste-menu-button (frame)
make(<menu-button>, label: "Paste",
activate-callback: not-yet-implemented,
accelerator: make-keyboard-gesture(#"v", #"control"),
documentation: "Paste the selection in the clipboard at the current position.");
//Commands in the Task menu
pane add-menu-button (frame)
make(<menu-button>, label: "Add...",
activate-callback: frame-add-task,
accelerator: make-keyboard-gesture
(#"a", #"control", #"shift"),
documentation: "Add a new task.");
pane remove-menu-button (frame)
make(<menu-button>, label: "Remove",
activate-callback: frame-remove-task,
accelerator: make-keyboard-gesture
(#"d", #"control", #"shift"),
documentation:
"Remove the selected task from the list.");
//Commands in the Help menu
pane about-menu-button (frame)
make(<menu-button>, label: "About",
activate-callback: about-task,
accelerator: make-keyboard-gesture(#"f1"),
documentation:
"Display information about the application.");
// definition of buttons
pane add-button (frame)
make(<push-button>, label: "Add task",
activate-callback: frame-add-task);
pane remove-button (frame)
make(<push-button>, label: "Remove task",
activate-callback: frame-remove-task);
pane open-button (frame)
make(<push-button>, label: "Open file",
activate-callback: open-file);
pane save-button (frame)
make(<push-button>, label: "Save file",
activate-callback: save-file);
// definition of radio box
pane priority-box (frame)
make (<radio-box>,
items: $priority-items,
orientation: #"horizontal",
label-key: first,
value-key: second,
value: #"medium",
activate-callback: not-yet-implemented);
// definition of tool bar
pane task-tool-bar (frame)
make(<tool-bar>,
child: horizontally ()
frame.open-button;
frame.save-button;
frame.add-button;
frame.remove-button
end);
// definition of status bar
pane task-status-bar (frame)
make(<status-bar>, label: "Task Manager");
// definition of list
pane task-list (frame)
make (<list-box>,
items: frame.frame-task-list.task-list-tasks,
label-key: task-name,
lines: 15,
value-changed-callback: note-task-selection-change);
// main layout
pane task-layout (frame)
vertically ()
frame.task-list;
frame.priority-box;
end;
// activation of frame elements
layout (frame) frame.task-layout;
tool-bar (frame) frame.task-tool-bar;
status-bar (frame) frame.task-status-bar;
menu-bar (frame) frame.task-menu-bar;
// frame title
keyword title: = "Task List Manager";
end frame <task-frame>;
define method initialize
(frame :: <task-frame>, #key) => ()
next-method();
refresh-task-frame(frame);
end method initialize;
define method prompt-for-task
(#key title = "Type text of new task", owner)
=> (name :: false-or(<string>),
priority :: false-or(<priority>))
let task-text
= make(<text-field>,
label: "Task text:",
activate-callback: exit-dialog);
let priority-field
= make(<radio-box>,
items: $priority-items,
label-key: first,
value-key: second,
value: #"medium");
let frame-add-task-dialog
= make(<dialog-frame>,
title: title,
owner: owner,
layout: vertically ()
task-text;
priority-field
end,
input-focus: task-text);
if (start-dialog(frame-add-task-dialog))
values(gadget-value(task-text), gadget-value(priority-field))
end
end method prompt-for-task;
define function make-keyboard-gesture
(keysym :: <symbol>, #rest modifiers)
=> (gesture :: <keyboard-gesture>)
make(<keyboard-gesture>, keysym: keysym, modifiers: modifiers)
end function make-keyboard-gesture;
define function not-yet-implemented (gadget :: <gadget>) => ()
notify-user("Not yet implemented!", owner: sheet-frame(gadget))
end function not-yet-implemented;
define method start-task () => ()
let frame
= make(<task-frame>);
start-frame(frame);
end method start-task;
define method frame-add-task (gadget :: <gadget>) => ()
let frame = sheet-frame(gadget);
let task-list = frame-task-list(frame);
let (name, priority) = prompt-for-task(owner: frame);
if (name & priority)
let new-task = make(<task>, name: name, priority: priority);
add-task(task-list, new-task);
refresh-task-frame(frame);
frame-selected-task(frame) := new-task
end
end method frame-add-task;
define method frame-remove-task (gadget :: <gadget>) => ()
let frame = sheet-frame(gadget);
let task = frame-selected-task(frame);
let task-list = frame-task-list(frame);
if (notify-user(format-to-string
("Really remove task %s", task.task-name),
owner: frame, style: #"question"))
frame-selected-task(frame) := #f;
remove-task(task-list, task);
refresh-task-frame(frame)
end
end method frame-remove-task;
define method frame-selected-task
(frame :: <task-frame>) => (task :: false-or(<task>))
let list-box = task-list(frame);
gadget-value(list-box)
end method frame-selected-task;
define method frame-selected-task-setter
(task :: false-or(<task>), frame :: <task-frame>)
=> (task :: false-or(<task>))
let list-box = task-list(frame);
gadget-value(list-box) := task;
note-task-selection-change(frame);
task
end method frame-selected-task-setter;
define method refresh-task-frame
(frame :: <task-frame>) => ()
let list-box = frame.task-list;
let task-list = frame.frame-task-list;
let modified? = task-list.task-list-modified?;
let tasks = task-list.task-list-tasks;
if (gadget-items(list-box) == tasks)
update-gadget(list-box)
else
gadget-items(list-box) := tasks
end;
gadget-enabled?(frame.save-button) := modified?;
gadget-enabled?(frame.save-menu-button) := modified?;
note-task-selection-change(frame);
end method refresh-task-frame;
define method note-task-selection-change
(gadget :: <gadget>) => ()
let frame = gadget.sheet-frame;
note-task-selection-change(frame)
end method note-task-selection-change;
define method note-task-selection-change
(frame :: <task-frame>) => ()
let task = frame-selected-task(frame);
if (task)
frame.priority-box.gadget-value := task.task-priority;
end;
let selection? = (task ~= #f);
frame.remove-button.gadget-enabled? := selection?;
frame.remove-menu-button.gadget-enabled? := selection?;
end method note-task-selection-change;
define method open-file
(gadget :: <gadget>) => ()
let frame = sheet-frame(gadget);
let task-list = frame-task-list(frame);
let filename
= choose-file(frame: frame,
default: task-list.task-list-filename,
direction: #"input");
if (filename)
let task-list = load-task-list(filename);
if (task-list)
frame.frame-task-list := task-list;
refresh-task-frame(frame)
else
notify-user
(format-to-string("Failed to open file %s", filename),
owner: frame)
end
end
end method open-file;
define method save-file
(gadget :: <gadget>) => ()
let frame = sheet-frame(gadget);
let task-list = frame-task-list(frame);
save-as-file(gadget, filename: task-list.task-list-filename)
end method save-file;
define method save-as-file
(gadget :: <gadget>, #key filename) => ()
let frame = sheet-frame(gadget);
let task-list = frame-task-list(frame);
let filename
= filename
| choose-file(frame: frame,
default: task-list.task-list-filename,
direction: #"output");
if (filename)
if (save-task-list(task-list, filename: filename))
frame.frame-task-list := task-list;
refresh-task-frame(frame)
else
notify-user(format-to-string
("Failed to save file %s", filename),
owner: frame)
end
end
end method save-as-file;
define function about-task (gadget :: <gadget>) => ()
notify-user("Task List Manager", owner: sheet-frame(gadget))
end function about-task;
define method exit-task (gadget :: <gadget>) => ()
let frame = sheet-frame(gadget);
let task-list = frame-task-list(frame);
save-file (gadget);
exit-frame(frame)
end method exit-task;
define method main (arguments :: <sequence>) => ()
// handle the arguments
start-task();
end method main;
begin
main(application-arguments()) // Start the application!
end;
Contents of the file task-list.dylan:
Module: task-list
Synopsis: Task List Manager.
Author: Harlequin Group plc
Copyright: (C) 1998, Harlequin Group plc. All rights reserved.
define class <task-list> (<object>)
constant slot task-list-tasks = make(<stretchy-vector>),
init-keyword: tasks:;
slot task-list-filename :: false-or(<string>) = #f,
init-keyword: filename:;
slot task-list-modified? :: <boolean> = #f;
end class <task-list>;
define constant <priority> = one-of(#"low", #"medium", #"high");
define class <task> (<object>)
slot task-name :: <string>,
required-init-keyword: name:;
slot task-priority :: <priority>,
required-init-keyword: priority:;
end class <task>;
define function add-task
(task-list :: <task-list>, task :: <task>) => ()
add!(task-list.task-list-tasks, task);
task-list.task-list-modified? := #t
end function add-task;
define function remove-task
(task-list :: <task-list>, task :: <task>) => ()
remove!(task-list.task-list-tasks, task);
task-list.task-list-modified? := #t
end function remove-task;
define function save-task-list
(task-list :: <task-list>, #key filename)
=> (saved? :: <boolean>)
let filename = filename | task-list-filename(task-list);
with-open-file (stream = filename, direction: #"output")
for (task in task-list.task-list-tasks)
format(stream, "%s\n%s\n",
task.task-name, as(<string>, task.task-priority))
end
end;
task-list.task-list-modified? := #f;
task-list.task-list-filename := filename;
#t
end function save-task-list;
define function load-task-list
(filename :: <string>) => (task-list :: false-or(<task-list>))
let tasks = make(<stretchy-vector>);
block (return)
with-open-file (stream = filename, direction: #"input")
while (#t)
let name = read-line(stream, on-end-of-stream: #f);
unless (name) return() end;
let priority = read-line(stream, on-end-of-stream: #f);
unless (priority)
error("Unexpectedly missing priority!")
end;
let task = make(<task>, name: name,
priority: as(<symbol>, priority));
add!(tasks, task)
end
end
end;
// debug-message("Tasks: %=", tasks);
make(<task-list>, tasks: tasks, filename: filename)
end function load-task-list;