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Characteristics:
GUI To-Do list:
#!/usr/bin/env spry
# A sample Spry application that is a trivial todolist app
# using a RocksDB as storage.
# First we need to initialize libui. Since spry and ispry
# has the spryui VM module built in, we have access
# to a set of words for libui. One is a func called uiInit
# that needs to be called to initialize libui.
# Calling a func (Spry function) is done simply by writing
# it's name, no need for () at the end since Spry does not
# use parentheses for parameter passing.
uiInit
# Variable holding our rocksdb. We do not declare variables
# in Spry, we simply create them by assignment. Assignment is
# done using the "=" word. In Spry we have nil as default value,
# in this case we set it to nil, which in fact is not needed
# in this application, but it's nice to show our top level
# variables!
db = nil
# The current todolist. We initalize it to an empty "block".
# A block in Spry is a List/Array/OrderedCollection in other
# languages, that can grow dynamically. It's worth noting
# that blocks are created at parse time, so executing this
# line of code multiple times will not create multiple blocks!
todos = []
# Open database and load todos. We create functions using
# func [...].
openDB = func [
# When assigning a variable in an outer scope, we need ..
# The ":path" means "pull in first parameter to this function
# and call it path.
db := openRocksDB :path
# The way precedence works in Spry we currently need
# parentheses sometimes, unfortunately.
todos := (db rockAt: "todos")
# Initialize as empty list or load existing list
todos nil? then: [
todos := []
saveTodos
] else: [
loadTodos
]
]
# Store in database
saveTodos = func [
db nil? else: [
db rockAt: "todos" put: todos
]
]
# Populate UI from the todolist
loadTodos = func [
todos do: [addToList :each]
]
# Close RocksDB and say bye befor exiting
byeBye = func [
db nil? else: [db closeRocksDB]
win message: "Bye bye" title: "Todolist"
]
# Given a todo of the form {id = 7 text = "blabla"} we create
# a row with a label of the text and a delete button.
newTodoRow = func [:todo
row = newHorizontalBox
label = newLabel: todo::text
# The delete button is tricky. First we need to pass
# a func (closure) instead of a pure block, otherwise
# we do not close over the todo parameter.
# Secondly, we need to find the index of the row to delete
# which we do by searching for the index of the todo with this
# unique id. The id is generated in the addButton by using a
# max + 1 trick to make sure it's not a duplicate id.
deleteButton = newButton: "Delete" onClicked: func [
id = todo::id
idx = (todos findIndex: func [:each each::id == id])
todoRows delete: idx
todos removeAt: idx
saveTodos
]
row add: label stretch: true
row add: deleteButton stretch: false
^row
]
addToList = func [
# Why is paren needed?
todoRows add: (newTodoRow :todo) stretch: false
]
# Build Window
menu = newMenu "File"
# Open an existing RocksDB
menu addItem: "Open ..." onClicked: [
path = (win openFile)
path nil? else: [
openDB path
]
]
# Making a new RocksDB
menu addItem: "New ..." onClicked: [
path = (win saveFile)
path nil? else: [
openDB path
]
]
# Add a Quit item in menu
menu addQuitItemShouldClose: [
byeBye
win destroy
uiQuit
^true
]
# Construct the application window
win = newWindow: "Todolist" width: 240 height: 400 hasBar: true
win margined: true
layout = newVerticalBox
todoRows = newVerticalBox
addTodo = newHorizontalBox
# Pick out text from the text entry field, create
# a todo (a Map), add it to the todos, and add a row in the UI.
# Finally saveTodos.
addButton = newButton: "Add" onClicked: func [
text = (addText text)
todo = {
text = text
id = ((todos max: [:todo todo::id] default: 0) + 1)
}
todos add: todo
addToList todo
saveTodos
]
addText = newEntryText: "Some stuff" onChanged: []
layout padded: true
group = newGroup "Todolist"
group
margined: true;
setChild: layout
# Wohoo, we can actually do cascades in Spry!
layout
add: todoRows stretch: true;
add: addTodo stretch: false
addTodo
add: addText stretch: true;
add: addButton stretch: false
win
setChild: group;
onClosingShouldClose: [byeBye true];
show;
uiMain
Last modified 12 July 2023