lua table constructor - lua

how do you make a default table and then use it when making other tables?
example
--default table
Button = {
x = 0,
y = 0,
w = 10,
h = 10,
Texture = "buttonimg.png",
onClick = function() end
}
newbutton = Button {
onClick = function()
print("button 1 pressed")
end
}
newbutton2 = Button {
x = 12,
onClick = function()
print("button 2 pressed")
end
}
newbuttons will get y, w, h and texture set to default value but anything set in the brackets get overwritten

You can achieve what you want by merging Doug's answer with your original scenario, like this:
Button = {
x = 0,
y = 0,
w = 10,
h = 10,
Texture = "buttonimg.png",
onClick = function() end
}
setmetatable(Button,
{ __call = function(self, init)
return setmetatable(init or {}, { __index = Button })
end })
newbutton = Button {
onClick = function()
print("button 1 pressed")
end
}
newbutton2 = Button {
x = 12,
onClick = function()
print("button 2 pressed")
end
}
(I actually tested this, it works.)
Edit: You can make this a bit prettier and reusable like this:
function prototype(class)
return setmetatable(class,
{ __call = function(self, init)
return setmetatable(init or {},
{ __index = class })
end })
end
Button = prototype {
x = 0,
y = 0,
w = 10,
h = 10,
Texture = "buttonimg.png",
onClick = function() end
}
...

If you set the new table's metatable's __index to point to Button it will use the default values from the Button table.
--default table
Button = {
x = 0,
y = 0,
w = 10,
h = 10,
Texture = "buttonimg.png",
onClick = function() end
}
function newButton () return setmetatable({},{__index=Button}) end
Now when you make buttons with newButton() they use the default values from the Button table.
This technique can be used for class or prototype object oriented programming. There are many examples here.

Related

Highcharts sankey node without links

I have a highcharts sankey diagram with two sides:
There are situations where some of my nodes have empty links (=with 0 weight). I would like the node to being displayed despite having no link from or to it.
Any chance I can achieve this?
I read on this thread that I have to fake it with weight=1 connexions, I could make the link transparent, and twitch the tooltip to hide those, but that's very painful for something that feels pretty basic.
Maybe a custom call of the generateNode call or something?
Thanks for the help
You can use the following wrap to show a node when the weight is 0.
const isObject = Highcharts.isObject,
merge = Highcharts.merge
function getDLOptions(
params
) {
const optionsPoint = (
isObject(params.optionsPoint) ?
params.optionsPoint.dataLabels : {}
),
optionsLevel = (
isObject(params.level) ?
params.level.dataLabels : {}
),
options = merge({
style: {}
}, optionsLevel, optionsPoint);
return options;
}
Highcharts.wrap(
Highcharts.seriesTypes.sankey.prototype,
'translateNode',
function(proceed, node, column) {
var translationFactor = this.translationFactor,
series = this,
chart = this.chart,
options = this.options,
sum = node.getSum(),
nodeHeight = Math.max(Math.round(sum * translationFactor),
this.options.minLinkWidth),
nodeWidth = Math.round(this.nodeWidth),
crisp = Math.round(options.borderWidth) % 2 / 2,
nodeOffset = column.sankeyColumn.offset(node,
translationFactor),
fromNodeTop = Math.floor(Highcharts.pick(nodeOffset.absoluteTop, (column.sankeyColumn.top(translationFactor) +
nodeOffset.relativeTop))) + crisp,
left = Math.floor(this.colDistance * node.column +
options.borderWidth / 2) + Highcharts.relativeLength(node.options.offsetHorizontal || 0,
nodeWidth) +
crisp,
nodeLeft = chart.inverted ?
chart.plotSizeX - left :
left;
node.sum = sum;
proceed.apply(this, Array.prototype.slice.call(arguments, 1));
if (1) {
// Draw the node
node.shapeType = 'rect';
node.nodeX = nodeLeft;
node.nodeY = fromNodeTop;
let x = nodeLeft,
y = fromNodeTop,
width = node.options.width || options.width || nodeWidth,
height = node.options.height || options.height || nodeHeight;
if (chart.inverted) {
x = nodeLeft - nodeWidth;
y = chart.plotSizeY - fromNodeTop - nodeHeight;
width = node.options.height || options.height || nodeWidth;
height = node.options.width || options.width || nodeHeight;
}
// Calculate data label options for the point
node.dlOptions = getDLOptions({
level: (this.mapOptionsToLevel)[node.level],
optionsPoint: node.options
});
// Pass test in drawPoints
node.plotX = 1;
node.plotY = 1;
// Set the anchor position for tooltips
node.tooltipPos = chart.inverted ? [
(chart.plotSizeY) - y - height / 2,
(chart.plotSizeX) - x - width / 2
] : [
x + width / 2,
y + height / 2
];
node.shapeArgs = {
x,
y,
width,
height,
display: node.hasShape() ? '' : 'none'
};
} else {
node.dlOptions = {
enabled: false
};
}
}
);
Demo:
http://jsfiddle.net/BlackLabel/uh6fp89j/
In the above solution, another node arrangement would be difficult to achieve and may require a lot of modifications beyond our scope of support.
You can consider using mentioned "tricky solution", since might return a better positioning result. This solution is based on changing 0 weight nodes on the chart.load() event and converting the tooltip as well, so it may require adjustment to your project.
chart: {
events: {
load() {
this.series[0].points.forEach(point => {
if (point.weight === 0) {
point.update({
weight: 0.1,
color: 'transparent'
})
}
})
}
}
},
tooltip: {
nodeFormatter: function() {
return `${this.name}: <b>${Math.floor(this.sum)}</b><br/>`
},
pointFormatter: function() {
return `${this.fromNode.name} → ${this.toNode.name}: <b>${Math.floor(this.weight)}</b><br/>`
}
},
Demo:
http://jsfiddle.net/BlackLabel/0dqpabku/

I cannot catch mouse signals on widgets within a wibox.container.scroll

I am constructing widgets dynamically from from the output of iw dev interface scan I then add them to a scroll box held in a wibox. The problem I find is that the mouse::enter and mouse::leave signals I connect the widgets to do not catch the mouse signals when inside the wibox.container.scroll. All the rest of the code works as intended and the signals are caught as intended if I omit the wibox.container.scroll wrapper.
The widget template to be added to the scroll container:
function wifitbox.new(ssid, screen, interface)
tbox = wibox.widget{
{
{
wibox.widget.textbox(ssid[2] .. " " .. ssid[3]),
{
wibox.widget.textbox(ssid[4]),
halign = "right",
widget = wibox.container.place
},
layout = wibox.layout.ratio.horizontal
},
margins = beautiful.xresources.apply_dpi(10, screen),
widget = wibox.container.margin
},
id = "tbox",
bg = beautiful.wifi_tbox_bg or "#928374",
shape = function(cr, width, height)
gears.shape.rounded_rect(cr, width, height, 5)
end,
widget = wibox.container.background
}
awful.spawn.easy_async('bash -c "sudo iw dev ' .. interface .. ' station dump | awk \'FNR == 1 {print($2)}\'"', function(stdout)
if(gears.string.split(stdout, "\n")[1] == ssid[1]) then
tbox.bg = "#b16286"
end
end)
tbox:connect_signal("mouse::enter", function()
tbox.bg_cache = tbox.bg
tbox.bg = "#689d6a"
end)
tbox:connect_signal("mouse::leave", function()
tbox.bg = tbox.bg_cache
end)
return tbox
end
The two :signal_connect() statements are the ones in questions.
The widgets are added to the scroll container a follows:
awful.spawn.with_line_callback(cmd, {
stdout = function(line)
local ssid = gears.string.split(line, "\t")
wifitbox_table:get_children_by_id("tbox_list")[1]:add(wifitbox(ssid, screen, interface))
end,
output_done = function()
self:set_widget(wifitbox_table)
end
})
The widget the containing the scroll container is as follows:
local wifitbox_table = wibox.widget{
scrollbtn,
{
id = "scroll_box",
speed = 100,
extra_space = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.container.scroll.vertical,
step_function = wibox.container.scroll.step_functions.linear_increase,
{
id= "tbox_list",
spacing = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.layout.fixed.vertical()
}
},
spacing = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.layout.fixed.vertical,
}
As I mentioned before if i remove the "scroll_box" widget around the "tbox_list" widget the signals connect without issue. But then obviously I don't get scrolling.
And finally all of it put together:
local awful = require('awful')
local wibox = require('wibox')
local gears = require('gears')
local beautiful = require('beautiful')
local wifimodal = { mt = {} }
local wifitbox = { mt = {} }
local setmetatable = setmetatable
function wifitbox.new(ssid, screen, interface)
tbox = wibox.widget{
{
{
wibox.widget.textbox(ssid[2] .. " " .. ssid[3]),
{
wibox.widget.textbox(ssid[4]),
halign = "right",
widget = wibox.container.place
},
layout = wibox.layout.ratio.horizontal
},
margins = beautiful.xresources.apply_dpi(10, screen),
widget = wibox.container.margin
},
id = "tbox",
bg = beautiful.wifi_tbox_bg or "#928374",
shape = function(cr, width, height)
gears.shape.rounded_rect(cr, width, height, 5)
end,
widget = wibox.container.background,
}
awful.spawn.easy_async('bash -c "sudo iw dev ' .. interface .. ' station dump | awk \'FNR == 1 {print($2)}\'"', function(stdout)
if(gears.string.split(stdout, "\n")[1] == ssid[1]) then
tbox.bg = "#b16286"
end
end)
tbox:connect_signal("mouse::enter", function()
tbox.bg_cache = tbox.bg
tbox.bg = "#689d6a"
end)
tbox:connect_signal("mouse::leave", function()
tbox.bg = tbox.bg_cache
end)
return tbox
end
function wifitbox.mt.__call(_, ...)
return wifitbox.new(...)
end
setmetatable(wifitbox, wifitbox.mt)
function wifimodal.new(screen, interface, curSSID)
self = wibox {
screen = screen,
width = screen.geometry.width / 5,
type = 'modal',
height = screen.workarea.height/2,
x = screen.geometry.width - screen.geometry.width/5,
y = beautiful.xresources.apply_dpi(beautiful.wibar_height or 25, screen),
ontop = true,
visible = true,
bg = beautiful.bg_normal,
fg = "black",
opacity = 0.8,
shape = function(cr, width, height)
gears.shape.rounded_rect(cr, width, height, 5)
end
}
self:connect_signal('mouse::leave', function()
self.visible = false
self = nil
end)
local scrollbtn = wibox.widget{
{
{
widget = wibox.widget.imagebox,
resize = true,
image = gears.filesystem.get_configuration_dir() .. "widgets/wifi/arrow_up.png",
forced_height = beautiful.xresources.apply_dpi(25, screen),
},
widget = wibox.container.place,
valign = "center",
},
shape = function(cr, width, height)
gears.shape.rounded_rect(cr, width, height, 5)
end,
widget = wibox.container.background,
bg = beautiful.wifi_scroll_btn_bg or "#d79921",
}
scrollbtn:connect_signal("mouse::enter", function()
scrollbtn:emit_signal_recursive("scroll::continue")
scrollbtn.bg = beautiful.wifi_scroll_btn_bg_hover or "#458588"
end)
scrollbtn:connect_signal("mouse::leave", function()
scrollbtn:emit_signal_recursive("scroll::pause")
scrollbtn.bg = beautiful.wifi_scroll_btn_bg or "#d79921"
end)
local scan_awk = gears.filesystem.get_configuration_dir() .. "widgets/wifi/scan.awk"
local cmd = 'bash -c "sudo iw ' .. interface .. ' scan | awk -f ' .. scan_awk .. '"'
local wifitbox_table = wibox.widget{
scrollbtn,
{
id = "scroll_box",
speed = 100,
extra_space = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.container.scroll.vertical,
step_function = wibox.container.scroll.step_functions.linear_increase,
{
id= "tbox_list",
spacing = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.layout.fixed.vertical()
}
},
spacing = beautiful.xresources.apply_dpi(5, screen),
layout = wibox.layout.fixed.vertical,
}
local scrollbox = wifitbox_table:get_children_by_id("scroll_box")[1]
scrollbox:pause()
wifitbox_table:connect_signal("scroll::continue", function()
scrollbox:continue()
end)
wifitbox_table:connect_signal("scroll::pause", function()
scrollbox:pause()
end)
awful.spawn.with_line_callback(cmd, {
stdout = function(line)
local ssid = gears.string.split(line, "\t")
wifitbox_table:get_children_by_id("tbox_list")[1]:add(wifitbox(ssid, screen, interface))
end,
output_done = function()
self:set_widget(wifitbox_table)
end
})
return self
end
function wifimodal.mt.__call(_, ...)
return wifimodal.new(...)
end
return setmetatable(wifimodal, wifimodal.mt)
Here is a screen shot for some context:
Also, if you don't have the answer but notice something else you can critic feel free. Thank you
The problem I find is that the mouse::enter and mouse::leave signals I connect the widgets to do not catch the mouse signals when inside the wibox.container.scroll
The third sentence on https://awesomewm.org/doc/api/classes/wibox.container.scroll.html is:
Please note that mouse events do not propagate to widgets inside of the scroll container.
So, this is "working as intended".
Also: https://github.com/awesomeWM/awesome/issues/3076

Editing a subtable inside a maintable using a function inside the maintable

Is it possible to edit the contents of a table which is inside another table using a function?
local MainTable = {
subtable = {
x = 0,
y = 0
},
addX = function()
subtable.x = subtable.x + 1
end
}
I'm getting the error attempt to index ? (a nil value)
Is it possible to achieve this?
It works outside the table, I used:
print(MainTable.subtable.x+1)
How come it doesn't work inside the table? Does tables being objects play a role?
Thank you!
Lua tables aren't objects; just because you're declaring addX inside MainTable, it is not aware of anything else inseide MainTable.
One solution would be:
local MainTable
MainTable = {
...
addX = function()
MainTable.subtable.x = MainTable.subtable.x + 1
end
}
but a better way would be
local MainTable = {
subtable = {
x = 0,
y = 0
}
}
function MainTable:addX()
self.subtable.x = self.subtable.x + 1
end
-- Use it as:
MainTable:addX()

Lua - set table(anonymous) value

return{
initime = 1;
isneed= true; -- need to modify
testfn=function()
isneed = false; ---how to modify the "isneed" value?
end
}
i wanna modify the isneed's value,i have try like this
local testdata;
testdata={
initime = 1;
isneed= true;
testfn=function()
testdata.isneed = false;
end
}
return testdata;
but the code that i dont want,i think have another way to set the value.
Building on #luther's comment, the code you have in your second example should work.
local testdata = {
initime = 1,
isneed = true,
testfn = function()
testdata.isneed = false
return
end
}
print(testdata.isneed)
testdata.testfn()
print(test.data.isneed)
This should output the following:
true
false
Alternatively, if you wanted to get a little fancier, you could use a metatable to overload the call operator for your table testdata:
local testdata = {
initime = 1,
isneed = true,
testfn = function()
testdata.isneed = false
return
end
}
testdata = setmetatable(testdata, {
__call = function(self)
return self.testfn()
end
})
print(testdata.isneed)
testdata()
print(testdata.isneed)
This example's output is equivalent to the above output. Depending on what exactly you wish to accomplish with your code, overloading the call operator with a metatable could offer you some more flexibility. Using this approach, you could change your code slightly like this, making use of the self parameter in the __call function:
local testdata = setmetatable({initime = 1, isneed = true}, {
__call = function(self)
self.isneed = false
return
end
})
print(testdata.isneed)
testdata()
print(testdata.isneed)
This will produce the same output as the first example.

How can I access a lua file with a tab bar?

I am having an error when trying to access a file with a tab bar constructed within it. Does anyone know what I am doing wrong. Corona SDK tells me my error is in the section of code where I actually create the tab bar, not the buttons. Thanks
Below is my code for the MainPage.lua scene in which the tab bar is created.
local tabBar = nil
function scene: create (event)
local group = scene.view
local tabButtons =
{
{
width = 20,
height = 32,
defaultFile = "assets/home.png",
overFile = "assets/PressHome.png",
label = "Home",
font = tabLabelFont,
size = tabLabelFontSize,
onPress = function() composer.gotoScene( "Home" ); end,
},
{
width = 20,
height = 32,
defaultFile = "assets/Explore.png",
overFile = "assets/Explore.png",
label = "Explore",
font = tabLabelFont,
size = tabLabelFontSize,
onPress = function() composer.gotoScene( "Explore" ); end,
},
{
width = 20,
height = 32,
defaultFile = "assets/Post.png",
overFile = "assets/Post.png",
label = "Post",
font = tabLabelFont,
size = tabLabelFontSize,
onPress = function() composer.gotoScene( "Post" ); end,
},
{
width = 20,
height = 32,
defaultFile = "assets/Notification.png",
overFile = "assets/Notification.png",
label = "Notification",
font = tabLabelFont,
size = tabLabelFontSize,
onPress = function() composer.gotoScene( "Notification" ); end,
},
{
width = 20,
height = 32,
defaultFile = "assets/Profile.png",
overFile = "assets/Profile.png",
label = "Profile",
font = tabLabelFont,
size = tabLabelFontSize,
onPress = function() composer.gotoScene( "Profile" ); end,
}
}
-- Create a tab-bar and place it at the bottom of the screen
tabBar = widget.newTabBar
{
top = display.contentHeight - 50,
width = display.contentWidth,
backgroundFile = "assets/tabbar.png",
tabSelectedLeftFile = "assets/tabBar_tabSelectedLeft.png",
tabSelectedMiddleFile = "assets/tabBar_tabSelectedMiddle.png",
tabSelectedRightFile = "assets/tabBar_tabSelectedRight.png",
tabSelectedFrameWidth = 20,
tabSelectedFrameHeight = 52,
buttons = tabButtons
}
group: insert(tabBar)
composer.gotoScene("Home")
end
scene:addEventListener( "create", scene )
return scene
here is the method from the log in page that is supposed to access the tab bar page.
local function EnterPage( event )
composer.gotoScene("MainPage")
end
this is what the error is saying
stack traceback:
?: in function '?'
?: in function <?:703>
(tail call): ?
?: in function <?:122>
(tail call): ?
MainPage.lua:127: in main chunk
[C]: in function 'require'
?: in function <?:797>
(tail call): ?
LogIn.lua:78: in function <LogIn.lua:70>
?: in function <?:218>
line 127 of Main Page is the line that states "tabBar = widget.newTabBar"
The errors in the log in page just go to the gotoScene(MainPage) method
"File: ? Attempt to index a nil value" is very helpful: it says that you are doing an operation of the form a.b like a.b = something or a.b() where a is nil. Given the line it happens on, this is surely because you forgot
widget = require 'widget'
near the top of your file.
If that line is already there (in MainPage.lua), then check that widget hasn't been overwritten:
print('widget is', widget)
tabBar = widget.newTabBar
...
If it is not nil then you have made an error in the information you posted (wrong line number, etc) or maybe you tried many things and info got mixed up. You could try, just to be sure,
widget = require 'widget'
tabBar = widget.newTabBar
If that works, then you know you are overwriting widget somewhere in your MainPage.lua, in code not shown. You should also try
test = widget.newButton
{
left = 100, top = 200,
label = "Default",
onEvent = function() print('hi') end
}
If that works, but the newTabBar still doesn't work, try replacing your options with those of the example on corona newTabBar site.

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