i prepare a dropdown menu with 2 or more items
İ want to take the double value and use it in a calculation
My entries are Aluminium 2.75 ----Steel 7.85 etc.
I define
String density_choose = "Steel 7.25";
DropdownButton<String>(
value: density_choose,
items: density.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text("malzeme:$value"),
);
}).toList(),
icon: Icon(Icons.arrow_drop_down),
onChanged: (var secilenVeri) {
setState(() {
density_choose = secilenVeri!;
});
},
),
My calculation
double sum = int.parse(kenar.text) *
int.parse(kenar.text) *
int.parse(yukseklik.text) *
int.parse(yukseklik.text) *double.parse(density_choose.split(" ")[2])/
1000000;
output = sum.toString();
I dont have any problem in syntax but I cant take the double
I think I found the issue. It's coming from this density_choose.split(" ")[2].
You should be getting the 1 not the [2].
density_choose.split(" ")[1]
Since:
density_choose = 'Steel 7.25';
Then:
density_choose.split(" ") = ['Steel', '7.25']
density_choose.split(" ")[0] = 'Steel';
density_choose.split(" ")[1] = '7.25';
Related
I am using as a Latex renderer in my flutter project. I want to add a latex value to an existing Catex object. I have a List of Strings which hold latex values and a listview to display them in order. I want to add a list item to the Catex every time an OnTap method is called.
so far, + operator is not supported
The operator '+' isn't defined for the type 'CaTeX'.
CaTeX catex = r'\mu =: \sqrt{x}' as CaTeX;
int value = 0;
...
List<String> get data => [
r'\mu =: \sqrt{x}',
r'\eta = 7^\frac{4}{2}',
r'\epsilon = \frac 2 {3 + 2}',
r'x_{initial} = \frac {20x} {\frac{15}{3}}',
// ignore: no_adjacent_strings_in_list
r'\colorbox{red}{bunt} \boxed{ '
r'\rm{\sf{\bf{'
r'\textcolor{red} s \textcolor{pink} i \textcolor{purple}m '
r'\textcolor{blue}p \textcolor{cyan} l \textcolor{teal} e} '
r'\textcolor{lime}c \textcolor{yellow}l \textcolor{amber} u '
r'\textcolor{orange} b}}}',
r'\TeX',
r'\LaTeX',
r'\KaTeX',
r'\CaTeX',
'x_i=a^n',
r'\hat{y} = H y',
r'12^{\frac{\frac{2}{7}}{1}}',
r'\varepsilon = \frac{\frac{2}{1}}{3}',
r'\alpha\beta\gamma\delta',
// ignore: no_adjacent_strings_in_list
r'\colorbox{black}{\textcolor{white} {black} } \colorbox{white} '
r'{\textcolor{black} {white} }',
r'\alpha\ \beta\ \ \gamma\ \ \ \delta',
r'\epsilon = \frac{2}{3 + 2}',
r'\tt {type} \textcolor{teal}{\rm{\tt {writer} }}',
'l = a * t * e * x',
r'\rm\tt{sp a c i n\ \bf\it g}',
r'5 = 1 \cdot 5',
'{2 + 3}+{3 +4 }=12',
r'\backslash \leftarrow \uparrow \rightarrow \$',
r'42\uparrow 99\Uparrow\ \ 19\downarrow 1\Downarrow',
'5x = 25',
r'10\cdot10 = 100',
'a := 96',
];
...
changeListItems(int val) {
setState(() {
this.value = val;
if (this.value != 0) {
catex += data[this.value];
}
});
}
...
body: ListView.builder(
itemCount: this.value,
itemBuilder: (context, index) {
return Column(children: [catex]);
}),
...
onTap: (int index) {
index == 0
? this.value = this.value - 1
: this.value = this.value + 1;
changeListItems(this.value);
}
You can override the + operator for the Catex class with an extension:
extension Sum on Catex{
Catex operator +(Catex other) {
return Catex(this.input + other.input);
}
}
This is not very reliable since it depends on the input property of the Catex Package. Also, you are storing a constant Widget in your class which is also not recommended.
Widgets are meant to be created during the Build process so the Flutter framework can work on it properly.
The correct way to do it would be to have in your state a String which contains the input that will be passed to the Catex:
String catexInput = r'\mu =: \sqrt{x}';
[...]
catexInput += data[this.value];
[...]
return Catex(catexInput);
Edit:
If you want to have a Column with multiple Catex Widgets, you can do the same thing except that your state will need to contain a list of Strings:
List<String> catexInputs = [r'\mu =: \sqrt{x}'];
[...]
catexInput.add(data[this.value]);
[...]
return Column(children: [for (String input in catexInput) Catex(input)]);;
How can I have list of boxes containing all words I render, I need it to determine which word is user long clicking?
In other words how can I find what maxRange so I can use getBoxesForRange in code below?
My code :
var pin = Offset(0, 0);
// To create a paragraph of text, we use ParagraphBuilder.
final ui.ParagraphBuilder builder = ui.ParagraphBuilder(
ui.ParagraphStyle(
textDirection: ui.TextDirection.rtl,
textAlign: ebookTextAlign,
fontFamily: "Asan",
fontSize: ebookMainTextSize,
),
)..pushStyle(ui.TextStyle(color: const ui.Color(0xFF000000)));
spans.forEach((spn) {
if (spn.localName == "p") builder.addText("\n");
builder.addText(spn.text + " ");
});
builder.pop();
paragraph = builder.build()
..layout(ui.ParagraphConstraints(width: size.width));
var list = new List<ExtendedTextBox>();
var boxes = paragraph.getBoxesForRange(0, maxRange);
I am tring to use a map to get words from a string and map them to a widget.
I have tried this but my problem is the key for the words doe and sister get the same keys so i end up getting only one of them
String theText = "my name is doe from http.doe.com, my sister is selly. doe and saqil are not sister friends of koiter.";
wordsMap = Map.fromIterable(text.split(' '),
key: (v) => v,
value: (v) => TextSpan(text: v));
so I tried the code below
Map mapMyWord = {};
// var wordsMap;
var splitForSize = text.split(' ').toList();
for(var t = 0;t<= splitForSize.length-1;t++){
mapMyWord[t] = {'$t':TextSpan(text: splitForSize[t])};
}
but In the second code when I tried to access mapMyWord.values.toList() it returns a list of map data again
[{0: TextSpan("my")}, {1: TextSpan("name")}, {2: TextSpan("is")}, {3: TextSpan("doe")}, {4: TextSpan("````http.codeish.com````,")}, ... ,{19: TextSpan("koiter")}]
so my main problem is how to get the values from here.
It returns maps because you're assigning maps with this line :
mapMyWord[t] = {'$t':TextSpan(text: splitForSize[t])};
So in the end you have a Map<Int, Map<String, TextSpan>>.
If you meant to turn the words of that sentence into a list of TextSpan, this would be the way :
var textSpanList = text.split(" ").map((word) => TextSpan(text: word)).toList();
If you want to do it directly in the widget tree, this would do it :
children: <Widget>[
for(var word in text.split(" "))
Text(word),
]
N.B: This last snippet requires a minimum SDK of 2.2.2 in the pubspec.yaml
In your second code, change the assignment part:
Map mapMyWord = {};
// var wordsMap;
var splitForSize = text.split(' ').toList();
for(var t = 0;t<= splitForSize.length-1;t++){
mapMyWord[t] = TextSpan(text: splitForSize[t]);
}
Then, mapMyWord.values.toList() will only return a list of TextSpan's. And if you want to get some specific value from the map:
int index = 1; //some number
print(mapMyWord[index]); //this will return one TextSpan
I have been changing a form based on REACT and this is something I am a newb with (been using it already for 4 months but just segments of it, sometimes actual progress with the programming is based on pure luck and every time on advices of good people found here).
Currently I have a task of re-developing a form of this look:
What I need to achieve is Calibration radios' behavior based on Type's selection: if argument calibration is set to 0 (zero) then disable option 'Accredited' and check second option automatically.
Edited: 19 Oct 2017
This creates the drop down, and the DD works great:
createSuggestInput(name) {
const { id, value, labels } = this.props;
const _t = this.props.intl.formatMessage;
var options = [
{ value: 'one', label: 'One', calibration: '0' },
{ value: 'two', label: 'Two ', calibration: '1' },
{ value: 'three', label: 'Three', calibration: '0' },
{ value: 'four', label: 'Four', calibration: '1' },
];
return <Select.Creatable
name = {`${id}_${name}`}
value = {this.state.brandSelect}
placeholder = {_t(translations.txtSuggest)}
options = {options}
onChange = {this._onChange.bind(this)}
label = {labels[name]}
key = {`${id}_${name}`}
promptTextCreator = { (label) => _t(translations.txtCreate) + ' ' + label + _t(translations.txtCreateEnter) }
/>;
}
When selected option's calibration value is ZERO, I need to update set of Calibration radio buttons, by disabling the option "Accredited" and at the same time checking the second option, "Not Accredited".
createRadioCalibration(name) {
const { id, value, labels } = this.props;
const _t = this.props.intl.formatMessage;
const ACCREDITATION_TYPES = [
[CALIBRATION_ACCREDITED, _t(messages.calibrationAccredited)],
[CALIBRATION_NOT_ACCREDITED, _t(messages.calibrationNotAccredited)]
];
return <FormChoiceGroup
type = "radio"
values = {ACCREDITATION_TYPES.map(mapValueArray)}
key = {`${id}_${name}`}
name = {`${id}_${name}`}
value = {value[name]}
handleChange = {this.handleFieldChangeFn(name)}
/>;
}
These two are rendered as follows:
render () {
const FIELDS = {
[CALIBRATION]: this.createRadioCalibration(CALIBRATION),
[TYPE]: this.createSuggestInput(TYPE),
};
return (
<div className="repair-form-device repair-form-device-field-row">
<div className="repair-form-device-id">
{id + 1}
</div>
<div className="clearfix repair-form-device-content">
<div className="">
{ FIELDS[TYPE] }
</div>
<div className="">
<label>{_t(messages.repair)}</label>
{ FIELDS[CALIBRATION] }
</div>
.....
And lastly the _onChange function:
_onChange(tool) {
const { id } = this.props;
this.setState({
brandSelect: tool
});
}
As I stated previously, I am stuck with the main task, which is manipulating the Calibration radio buttons.
I believe I can update its status inside the _onChange function, but everything I tested so far lead me nowhere.
Your patience is much appreciated!
I'm working on an application that will allow people to select which data fields they would like a form to have. I had it working but when I tried to move the form fields into a table for a bit of visual structure I'm running into a problem.
// Now print the form to a new div
array.forEach(selectedFields, function(item, i) {
var l = domConstruct.create("label", {
innerHTML: item + ': ',
class: "dataFieldLabel",
for: item
});
var r = new TextBox({
class: "dataField",
name: item,
label: item,
title: item
});
var a = domConstruct.toDom("<tr><td>" + l + r + "</td></tr>");
domConstruct.place(a, "displayDataForm");
When I run the code I can select the fields I want but instead of textboxes being drawn on the screen text like:
[object HTMLLabelElement][Widget dijit.form.TextBox, dijit_form_TextBox_0]
[object HTMLLabelElement][Widget dijit.form.TextBox, dijit_form_TextBox_1]
Is printed to the screen instead. I think this is because I am passing domConstruct.place a mixture of text and objects. Any ideas about how to work around this? Thanks!
Try this :
require(["dojo/_base/array", "dojo/dom-construct", "dijit/form/TextBox", "dojo/domReady!"], function(array, domConstruct, TextBox){
var selectedFields = ["Foo", "Bar", "Baz"];
array.forEach(selectedFields, function(item, i) {
var tr = domConstruct.create("tr", {}, "displayDataForm"),
td = domConstruct.create("td", {}, tr),
l = domConstruct.create("label", {
innerHTML: item + ': ',
'class': 'dataFieldLabel',
'for': item
}, td, 'first'),
r = new TextBox({
'class': 'dataField',
name: item,
title: item
}).placeAt(td, 'last');
});
});
This assumes you have this in your html :
<table id="displayDataForm"></table>
Don't forget to quote "class" and "for" as these are part of javascript's grammar.
The domConstruct functions will not work with widgets. You can create the html and then query for the input node and create the test box.
var root = dom.byId("displayDataForm");
domConstruct.place(root,
lang.replace(
'<tr><td><label class="dataFieldLabel" for="{0}>{0}:</label><input class="inputNode"></input></td></tr>',
[item])
);
query('.inputNode', root).forEach(function(node){
var r = new TextBox({
'class': "dataField",
name: item,
label: item,
title: item
});
});
Craig thank you for all your help, you were right except that in the call to domConstruct.place the first argument is the node to append and the second argument is the refNode to append to. Thank you.
// Now print the form to a new div
array.forEach(selectedFields, function(item, i) {
var root = dom.byId("displayDataForm");
domConstruct.place(lang.replace(
'<tr><td><label class="dataFieldLabel" for="{0}">{0}: </label><input class="dataField"></input></td></tr>',
[item]), root
);
query('.dataField', root).forEach(function(node) {
var r = new TextBox({
'class': "dataField",
name: item,
label: item,
title: item
});
});
});