Guides

Overview

Use events and notifications to synchronize application state, trigger custom workflows, or replace selected built-in UI behaviors.

The Flutter SDK exposes events in two ways:

• Reader callbacks: Pass callbacks directly to CPDFReaderWidget when creating the reader. Use these for reader lifecycle, viewer UI, style dialog, custom menu, annotation action, and form widget action callbacks.
• Listener events: Register events with CPDFReaderWidgetController.addEventListener() after the reader is created. Use these for annotation, form, and content editor object lifecycle events.

Event Summary

Category	API	Trigger Timing
Viewer	onPageChanged	Current page changes
Viewer	onSaveCallback	Document save completes
Viewer	onFillScreenChanged	Fullscreen state changes
Viewer	onTapMainDocAreaCallback	Main PDF page area is tapped
Viewer	onPageEditDialogBackPress	Back button in page edit dialog is tapped
Viewer	onIOSClickBackPressed	iOS top-left reader back button is tapped
Viewer	onSearchBackButtonTappedCallback	Search view back button is tapped
Viewer	onAddWatermarkDialogDismissedCallback	Add watermark dialog is dismissed
Annotations	onAnnotationCreationPreparedCallback	Signature, stamp, link, image, or Note creation is prepared
Annotations	onAnnotationStyleDialogDismissedCallback	Annotation style dialog is dismissed
Annotations	onInterceptAnnotationActionCallback	Existing Note or Link annotation is tapped and interception is enabled
Annotations	CPDFEvent.annotationsCreated	Annotation is created
Annotations	CPDFEvent.annotationsSelected	Annotation is selected
Annotations	CPDFEvent.annotationsDeselected	Annotation is deselected
Annotations	CPDFEvent.pencilDrawingCompleted	iOS Pencil drawing is completed
Annotations	CPDFEvent.pencilDrawingDiscarded	iOS Pencil drawing is discarded
Forms	onFormStyleDialogDismissedCallback	Form style dialog is dismissed
Forms	onInterceptWidgetActionCallback	A configured form widget is tapped and interception is enabled
Forms	CPDFEvent.formFieldsCreated	Form field is created
Forms	CPDFEvent.formFieldsSelected	Form field is selected
Forms	CPDFEvent.formFieldsDeselected	Form field is deselected
Content Editor	onContentEditorStyleDialogDismissedCallback	Content editor style dialog is dismissed
Content Editor	CPDFEvent.editorSelectionSelected	Editable content is selected
Content Editor	CPDFEvent.editorSelectionDeselected	Editable content is deselected
Custom Context Menu	onCustomContextMenuItemTappedCallback	Custom context menu item is tapped
Custom Toolbar Menu	onCustomToolbarItemTappedCallback	Custom toolbar item is tapped

Guides

Viewer Listen to page changes, document saves, fullscreen toggles, back button clicks, and related viewer UI events.

Annotations Listen to annotation creation, style dialog, action interception, selection, and iOS Pencil drawing events.

Forms Listen to form field style dialog, creation, selection, and deselection events.

Content Editor Listen to content editor style dialog and editable content selection events.

Custom Context Menu Listen to custom context menu item tap events.

Custom Toolbar Menu Listen to custom top toolbar menu item tap events.

Custom Note Annotation Creation Dialog Disable the default Note edit dialog after creation and present your own Flutter editing UI.