Kotlin UI DSL Version 1

Kotlin UI DSL allows creating UI forms with input components bound to state objects. The forms are built by using a declarative Kotlin syntax. It shares similarities with Jetpack Compose for Android and is intended to build UI forms or part of forms for, e.g. dialogs and settings pages.

The Kotlin UI DSL is not intended to build general UIs, like tool windows controls that trigger some actions and do not contain any input components bound to state objects. For this purpose, use custom Swing components from the IntelliJ Platform or the standard ones.

This document covers the Kotlin UI DSL in IntelliJ Platform 2019.2. A lot of the features described in this document are not available for plugins targeting earlier versions.

The Kotlin UI DSL Version 1 functions are located in the com.intellij.ui.layout package.

Layout Structure

Use panel to create UI:

panel {
  row {
    // child components
  }
}

Rows are created vertically from top to bottom, in the same order as lines of code that call row. Inside one row, you add components from left to right in the same order calls to factory method or () appear in each row. Every component is effectively placed in its own grid cell.

The label for the row can be specified as a parameter for the row method:

row("Parameters") { ... }

Rows can be nested. Components in a nested row block are considered to be subordinate to the containing row and are indented accordingly.

row {
  checkBox(...)
  row {
    textField(...) // indented relatively to the checkbox above
  }
}

To put multiple components in the same grid cell, wrap them in a cell method:

row {
  // These two components will occupy two columns in the grid
  label(...)
  textField(...)

  // These two components will be placed in the same grid cell
  cell {
    label(...)
    textField(...)
  }
}

To put a component on the right side of a grid row, use the right method:

row {
  rememberCheckBox()
  right {
    link("Forgot password")
  }
}

Adding Components

There are two ways to add child components. The recommended way is to use factory methods label, button, radioButton, link, etc. It allows you to create consistent UI and reuse common patterns.

These methods also support property bindings, allowing you to automatically load the value displayed in the component from a property and to store it back. The easiest way to do that is to pass a reference to a Kotlin bound property:

checkBox("Show tabs in single row", uiSettings::scrollTabLayoutInEditor)

Note that the bound property reference syntax also can be used to reference Java fields, but not getter/setter pairs.

Alternatively, many factory methods support specifying a getter/setter pair for cases when a property mapping is more complicated:

checkBox(
  "Show file extensions in editor tabs",
  { !uiSettings.hideKnownExtensionInTabs },
  { uiSettings.hideKnownExtensionInTabs = !it })

If you want to add a component for which there are no factory methods, you can simply invoke an instance of your component, using the () overloaded operator:

val customComponent = MyCustomComponent()
panel {
  row { customComponent() }
}

Supported Components

Labels

Use the label method:

label("Sample text")

Checkboxes

See examples above.

Radio Buttons

Radio button groups are created using the buttonGroup block. There are two ways to use it. If the selected radio button corresponds to a specific value of a single property, pass the property binding to the buttonGroup method and the specific values to radioButton functions:

buttonGroup(mySettings::providerType) {
  row { radioButton("In native Keychain", ProviderType.KEYCHAIN) }
  row { radioButton("In KeePass", ProviderType.KEEPASS) }
}

If the selected radio button is controlled by multiple boolean properties, use buttonGroup with no binding and specify property bindings for all but one of the radio buttons:

buttonGroup {
  row { radioButton("The tab on the left") }
  row { radioButton("The tab on the right", uiSettings::activeRightEditorOnClose) }
  row { radioButton("Most recently opened tab", uiSettings::activeMruEditorOnClose) }
}

Text Fields

Use the textField method for a simple text field:

row("Username:") {
    textField(settings::userName)
}

For entering numbers, use intTextField:

intTextField(uiSettings::editorTabLimit, columns = 4, range = EDITOR_TABS_RANGE)

For password text fields, there is no factory function available, so you need to use ():

val passwordField = JPasswordField()
val panel = panel {
  // ...
  row { passwordField() }
}

To specify the size of a text field, either pass the columns parameter as shown in the intTextField example above, or use growPolicy():

val userField = JTextField(credentials?.userName)
val panel = panel {
  row("Username:") { userField().growPolicy(GrowPolicy.SHORT_TEXT) }
}

Combo Boxes

Use the comboBox method with either a bound property, or a getter/setter pair:

comboBox(DefaultComboBoxModel<Int>(tabPlacements), uiSettings::editorTabPlacement)

comboBox<PgpKey>(
  pgpListModel,
  { getSelectedPgpKey() ?: pgpListModel.items.firstOrNull() },
  { mySettings.state.pgpKeyId = if (usePgpKey.isSelected) it?.keyId else null })

Spinners

Use the spinner method:

spinner(retypeOptions::retypeDelay, minValue = 0, maxValue = 5000, step = 50)

Link Label

Use the link method:

link("Forgot password?") {
  // handle click, e.g. showing dialog
}

To open URL in the browser, use browserLink:

browserLink("Open Homepage", "https://www.jetbrains.com")

Separators

Use the titledRow method and put the controls under the separator into the nested block:

titledRow("Appearance") {
  row { checkBox(...) }
}

Explanatory Text

Use the comment parameter:

checkBox(message("checkbox.smart.tab.reuse"),
       uiSettings::reuseNotModifiedTabs,
       comment = message("checkbox.smart.tab.reuse.inline.help"))

Integrating Panels with Property Bindings

A panel returned by the panel method is an instance of DialogPanel. This base class supports the standard apply(), reset(), and isModified() methods.

Dialogs

Reference: DialogWrapper

If you're using a DialogPanel as the main panel of a DialogWrapper, the apply() method will be automatically called when the dialog is closed using OK action. The other methods are unused in this case.

Use the focused() method to specify which control should be focused when the dialog is initialized:

return panel {
  row("Target class name:") {
    textField(::className).focused()
  }
}

Configurables

Reference: Settings Guide

If you're using the UI DSL to implement a Configurable, use BoundConfigurable as the base class. In this case, the Configurable methods will be automatically delegated to the panel.

Enabling and Disabling Controls

Use the enableIf method to bind the enabled state of a control to the values entered in other controls. The parameter of the method is a predicate.

checkBox("Show tabs in single row", uiSettings::scrollTabLayoutInEditor)
  .enableIf(myEditorTabPlacement.selectedValueIs(SwingConstants.TOP))

The available predicates are:

selected to check the selected state of a checkbox or radio button
selectedValueIs and selectedValueMatches to check the selected item in a combo box.

Predicates can be combined with and and or infix functions:

checkBox("Hide tabs if there is no space", uiSettings::hideTabsIfNeed)
  .enableIf(myEditorTabPlacement.selectedValueMatches { it != UISettings.TABS_NONE } and
              myScrollTabLayoutInEditorCheckBox.selected)

Examples

Sample usages in IntelliJ Platform IDEs:

User Interface	Implementation
Settings \| Editor \| Reader Mode	`ReaderModeConfigurable`
New Branch dialog in Git (Manage Git branches)	`GitNewBranchDialog`
Settings \| Tools \| Diff & Merge	`DiffSettingsConfigurable`
Settings \| Editor \| General \| Editor Tabs	`EditorTabsConfigurable`

FAQ

One Cell Is Minimum, Second One Is Maximum

Set CCFlags.growX and CCFlags.pushX for some component in the second cell.

Last modified: 02 July 2024