Ekhlass/Flutter_Documentation · Datasets at Hugging Face

text stringlengths 1 474
folder of your project (the one containing pubspec.yaml)
in VS Code and clicking Run > Start Debugging (F5).<topic_end>
<topic_start>
Launch DevTools
Once the debug session is active and the application has started,
the Open DevTools commands become available in the
VS Code command palette (F1):The chosen tool will be opened embedded inside VS Code.You can choose to have DevTools always opened in a browser with the
dart.embedDevTools setting, and control whether it opens as a full window or
in a new column next to your current editor with the dart.devToolsLocation
setting.A full list of Dart/Flutter settings are available
here or in the
VS Code settings editor.
Some recommendation settings for Dart/Flutter in VS Code can be found
here.You can also see whether DevTools is running and launch it in a browser from the
language status area (the {} icon next to Dart in the status bar).
<topic_end>
<topic_start>Install and run DevTools from the command line
To run Dart DevTools from the CLI, you must have dart on your path. Then
you can run the following command to launch DevTools:To upgrade DevTools, upgrade your Dart SDK. If a newer Dart SDK
includes a newer version of DevTools, dart devtools will automatically
launch this version. If which dart points to the Dart SDK included in
your Flutter SDK, then DevTools will be upgraded when you upgrade your
Flutter SDK to a newer version.When you run DevTools from the command line, you should see output that
looks something like:<topic_end>
<topic_start>
Start an application to debug
Next, start an app to connect to.
This can be either a Flutter application
or a Dart command-line application.
The command below specifies a Flutter app:You need to have a device connected, or a simulator open,
for flutter run to work. Once the app starts, you’ll see a
message in your terminal that looks like the following:Open the DevTools instance connected to your app
by opening the second link in Chrome.This URL contains a security token,
so it’s different for each run of your app.
This means that if you stop your application and re-run it,
you need to connect to DevTools again with the new URL.<topic_end>
<topic_start>
Connect to a new app instance
If your app stops running
or you opened DevTools manually,
you should see a Connect dialog:You can manually connect DevTools to a new app instance
by copying the Observatory link you got from running your app,
such as http://127.0.0.1:52129/QjqebSY4lQ8=/
and pasting it into the connect dialog:
<topic_end>
<topic_start>Using the Flutter inspector
info Note
The inspector works with all Flutter applications.<topic_end>
<topic_start>
What is it?
The Flutter widget inspector is a powerful tool for visualizing and
exploring Flutter widget trees. The Flutter framework uses widgets
as the core building block for anything from controls
(such as text, buttons, and toggles),
to layout (such as centering, padding, rows, and columns).
The inspector helps you visualize and explore Flutter widget
trees, and can be used for the following:<topic_end>
<topic_start>
Get started
To debug a layout issue, run the app in debug mode and
open the inspector by clicking the Flutter Inspector
tab on the DevTools toolbar.info Note
You can still access the Flutter inspector directly from
Android Studio/IntelliJ, but you might prefer the
more spacious view when running it from DevTools
in a browser.<topic_end>
<topic_start>
Debugging layout issues visually
The following is a guide to the features available in the
inspector’s toolbar. When space is limited, the icon is
used as the visual version of the label.<topic_end>
<topic_start>
Inspecting a widget
You can browse the interactive widget tree to view nearby
widgets and see their field values.To locate individual UI elements in the widget tree,
click the Select Widget Mode button in the toolbar.
This puts the app on the device into a “widget select” mode.
Click any widget in the app’s UI; this selects the widget on the
app’s screen, and scrolls the widget tree to the corresponding node.
Toggle the Select Widget Mode button again to exit
widget select mode.When debugging layout issues, the key fields to look at are the
size and constraints fields. The constraints flow down the tree,
and the sizes flow back up. For more information on how this works,
see Understanding constraints.<topic_end>
<topic_start>
Flutter Layout Explorer
The Flutter Layout Explorer helps you to better understand
Flutter layouts.For an overview of what you can do with this tool, see
the Flutter Explorer video:You might also find the following step-by-step article useful:<topic_end>
<topic_start>
Using the Layout Explorer
From the Flutter Inspector, select a widget. The Layout Explorer
supports both flex layouts and fixed size layouts, and has
specific tooling for both kinds.<topic_end>
<topic_start>Flex layouts
When you select a flex widget (for example, Row, Column, Flex)
or a direct child of a flex widget, the flex layout tool will
appear in the Layout Explorer.The Layout Explorer visualizes how Flex widgets and their
children are laid out. The explorer identifies the main axis
and cross axis, as well as the current alignment for each

folder of your project (the one containing pubspec.yaml)

in VS Code and clicking Run > Start Debugging (F5).<topic_end>

<topic_start>

Launch DevTools

Once the debug session is active and the application has started,

the Open DevTools commands become available in the

VS Code command palette (F1):The chosen tool will be opened embedded inside VS Code.You can choose to have DevTools always opened in a browser with the

dart.embedDevTools setting, and control whether it opens as a full window or

in a new column next to your current editor with the dart.devToolsLocation

setting.A full list of Dart/Flutter settings are available

here or in the

VS Code settings editor.

Some recommendation settings for Dart/Flutter in VS Code can be found

here.You can also see whether DevTools is running and launch it in a browser from the

language status area (the {} icon next to Dart in the status bar).

<topic_end>

<topic_start>Install and run DevTools from the command line

To run Dart DevTools from the CLI, you must have dart on your path. Then

you can run the following command to launch DevTools:To upgrade DevTools, upgrade your Dart SDK. If a newer Dart SDK

includes a newer version of DevTools, dart devtools will automatically

launch this version. If which dart points to the Dart SDK included in

your Flutter SDK, then DevTools will be upgraded when you upgrade your

Flutter SDK to a newer version.When you run DevTools from the command line, you should see output that

looks something like:<topic_end>

<topic_start>

Start an application to debug

Next, start an app to connect to.

This can be either a Flutter application

or a Dart command-line application.

The command below specifies a Flutter app:You need to have a device connected, or a simulator open,

for flutter run to work. Once the app starts, you’ll see a

message in your terminal that looks like the following:Open the DevTools instance connected to your app

by opening the second link in Chrome.This URL contains a security token,

so it’s different for each run of your app.

This means that if you stop your application and re-run it,

you need to connect to DevTools again with the new URL.<topic_end>

<topic_start>

Connect to a new app instance

If your app stops running

or you opened DevTools manually,

you should see a Connect dialog:You can manually connect DevTools to a new app instance

by copying the Observatory link you got from running your app,

such as http://127.0.0.1:52129/QjqebSY4lQ8=/

and pasting it into the connect dialog:

<topic_end>

<topic_start>Using the Flutter inspector

info Note

The inspector works with all Flutter applications.<topic_end>

<topic_start>

What is it?

The Flutter widget inspector is a powerful tool for visualizing and

exploring Flutter widget trees. The Flutter framework uses widgets

as the core building block for anything from controls

(such as text, buttons, and toggles),

to layout (such as centering, padding, rows, and columns).

The inspector helps you visualize and explore Flutter widget

trees, and can be used for the following:<topic_end>

<topic_start>

Get started

To debug a layout issue, run the app in debug mode and

open the inspector by clicking the Flutter Inspector

tab on the DevTools toolbar.info Note

You can still access the Flutter inspector directly from

Android Studio/IntelliJ, but you might prefer the

more spacious view when running it from DevTools

in a browser.<topic_end>

<topic_start>

Debugging layout issues visually

The following is a guide to the features available in the

inspector’s toolbar. When space is limited, the icon is

used as the visual version of the label.<topic_end>

<topic_start>

Inspecting a widget

You can browse the interactive widget tree to view nearby

widgets and see their field values.To locate individual UI elements in the widget tree,

click the Select Widget Mode button in the toolbar.

This puts the app on the device into a “widget select” mode.

Click any widget in the app’s UI; this selects the widget on the

app’s screen, and scrolls the widget tree to the corresponding node.

Toggle the Select Widget Mode button again to exit

widget select mode.When debugging layout issues, the key fields to look at are the

size and constraints fields. The constraints flow down the tree,

and the sizes flow back up. For more information on how this works,

see Understanding constraints.<topic_end>

<topic_start>

Flutter Layout Explorer

The Flutter Layout Explorer helps you to better understand

Flutter layouts.For an overview of what you can do with this tool, see

the Flutter Explorer video:You might also find the following step-by-step article useful:<topic_end>

<topic_start>

Using the Layout Explorer

From the Flutter Inspector, select a widget. The Layout Explorer

supports both flex layouts and fixed size layouts, and has

specific tooling for both kinds.<topic_end>

<topic_start>Flex layouts

When you select a flex widget (for example, Row, Column, Flex)

or a direct child of a flex widget, the flex layout tool will

appear in the Layout Explorer.The Layout Explorer visualizes how Flex widgets and their

children are laid out. The explorer identifies the main axis

and cross axis, as well as the current alignment for each