History of the destinations visited within a PDF Document. 更多...
import 语句: | import QtQuick.Pdf |
PdfPageNavigator remembers which destinations the user has visited in a PDF document, and provides the ability to traverse backward and forward.
[read-only] backAvailable : bool |
保持
true
若
back
destination is available in the history.
currentLocation : point |
This property holds the current location on the page that is being viewed.
currentPage : int |
This property holds the current page that is being viewed. If there is no current page, it holds
-1
.
currentZoom : real |
This property holds the magnification scale on the page that is being viewed.
[read-only] forwardAvailable : bool |
保持
true
若
forward
destination is available in the history.
jumped ( int page , point location , qreal zoom ) |
This signal is emitted when an abrupt jump occurs, to the specified page index, location on the page, and zoom level; but not when simply scrolling through the document one page at a time. That is, forward (), back () 和 jump () always emit this signal; update () does not.
注意:
相应处理程序是
onJumped
.
void back () |
Pops the stack, updates the currentPage , currentLocation and currentZoom properties to the most-recently-viewed destination, and then emits the jumped () 信号。
void forward () |
Goes back to the page, location and zoom level that was being viewed before back () was called, and then emits the jumped () 信号。
If a new destination was pushed since the last time back () was called, the forward() function does nothing, because there is a branch in the timeline which causes the "future" to be lost.
void jump ( int page , point location , qreal zoom , bool emitJumped ) |
Adds the given destination, consisting of
page
,
location
,和
zoom
, to the history of visited locations. If
emitJumped
is
false
,
jumped
() signal will not be emitted.
若
forwardAvailable
is
true
, calling this function represents a branch in the timeline which causes the "future" to be lost, and therefore
forwardAvailable
将改变为
false
.
void update ( int page , point location , qreal zoom ) |
Modifies the current destination, consisting of page , location and zoom .
This can be called periodically while the user is manually moving around the document, so that after back () is called, forward () will jump back to the most-recently-viewed destination rather than the destination that was last specified by jump ().
The
currentZoomChanged
,
currentPageChanged
and
currentLocationChanged
signals will be emitted if the respective properties are actually changed. The
jumped
signal is not emitted, because this operation represents smooth movement rather than a navigational jump.