### - o -

- offscreenMousePos : MouseInputSource
- offset : DropShadow
- offStrings : AudioPluginInstance::Parameter
- onChange : ComboBox , NetworkServiceDiscovery::AvailableServiceList
- onClick : Button
- onDefaultChange : ValueWithDefault
- onDragEnd : Slider
- onDragStart : Slider
- onEditorHide : Label
- onEditorShow : Label
- onErrorOccurred : CameraDevice , VideoComponent
- onEscapeKey : TextEditor
- onFocusLost : TextEditor
- ongoing : PushNotifications::Notification
- onHeightChange : MultiChoicePropertyComponent
- onPanelMove : SidePanel
- onPanelShowHide : SidePanel
- onPlaybackStarted : VideoComponent
- onPlaybackStopped : VideoComponent
- onReturnKey : TextEditor
- onShaderActivated : OpenGLGraphicsContextCustomShader
- onStateChange : Button
- onStrings : AudioPluginInstance::Parameter
- onTextChange : Label , TextEditor
- onValueChange : Slider
- openGLContext : OpenGLAppComponent
- optionNames : Block::ConfigMetaData , BlockConfigManager::ConfigDescription
- options : StandalonePluginHolder
- order : FlexItem , GridItem
- orderId : InAppPurchases::Purchase
- orientation : MouseEvent
- originalComponent : MouseEvent
- originatingComponent : ApplicationCommandTarget::InvocationInfo
- originRelativeToComponent : Drawable
- osxLibrarySubFolder : PropertiesFile::Options
- out : LowLevelGraphicsPostScriptRenderer
- output : AudioFormatWriter
- outputBuses : AudioProcessor::BusesLayout
- outputChannels : AudioDeviceManager::AudioDeviceSetup
- outputDeviceName : AudioDeviceManager::AudioDeviceSetup
- outputLayouts : AudioProcessor::BusesProperties
- overlapPixels : TabBarButton
- owner : TabBarButton