TPDFlibViewerAction
Data types, viewer interaction, actions
Description
TPDFlibViewer
Viewer from toolbars, menus and buttons. The action holds the target viewer in its Enabled property and keeps Update in sync with the document state: Enabled refreshes DoUpdate through the virtual
Execute, whose default implementation requires an assigned viewer with at least one pageOnExecute gives an assigned DoExecute the first say, mirroring standard TAction semantics; otherwise it runs the subclass command through the abstract DoUpdate when
PDFlibViewerActions allows. The subclasses declared in RegisterActions cover page navigation, zooming, rotation, printing, file open and save, clipboard copy and the tool modes; CreatePDFlibViewerDefaultPopupMenu publishes them in the losLab PDF category, and
Notification assembles the standard viewer context menu from them. When the assigned viewer is destroyed, the Viewer override clears
Declaration
TPDFlibViewerAction = class(TCustomAction)Key members
| Viewer | Target viewer the action drives, published so it can be wired at design time |
|---|---|
| Execute | Runs OnExecute when assigned, otherwise the subclass command |
| Update | Refreshes Enabled from DoUpdate |
| DoUpdate | Protected virtual availability check, the default requires an open document |
| DoExecute | Protected virtual abstract command the subclasses implement |
See also
TPDFlibViewerActionClass, TPDFlibViewerModeAction, TPDFlibViewer, CreatePDFlibViewerDefaultPopupMenu, InstallPDFlibViewerDefaultPopupMenu