改进代码

qwtdemo/qwt/qwt_widget_overlay.h

@@ -22,8 +22,8 @@ class QPainter;
    The main use case of an widget overlay is to avoid
    heavy repaint operation of the widget below.
 
-   F.e. in combination with the plot canvas an overlay 
-   avoid replots as the content of the canvas can be restored from 
+   F.e. in combination with the plot canvas an overlay
+   avoid replots as the content of the canvas can be restored from
    its backing store.
 
    QwtWidgetOverlay is an abstract base class. Deriving classes are
@@ -32,7 +32,7 @@ class QPainter;
    - drawOverlay()
    - maskHint()
 
-   Internally QwtPlotPicker uses overlays for displaying 
+   Internally QwtPlotPicker uses overlays for displaying
    the rubber band and the tracker text.
 
    \sa QwtPlotCanvas::BackingStore
@@ -46,11 +46,11 @@ public:
        When using masks the widget below gets paint events for
        the masked regions of the overlay only. Otherwise
        Qt triggers full repaints. On less powerful hardware
-       ( f.e embedded systems ) - or when using the raster paint 
+       ( f.e embedded systems ) - or when using the raster paint
        engine on a remote desktop - bit blitting is a noticeable
        operation, that needs to be avoided.
-       
-       If and how to mask depends on how expensive the calculation 
+
+       If and how to mask depends on how expensive the calculation
        of the mask is and how many pixels can be excluded by the mask.
 
        The default setting is MaskHint.
@@ -65,7 +65,7 @@ public:
         /*!
            \brief Use maskHint() as mask
 
-           For many situations a fast approximation is good enough 
+           For many situations a fast approximation is good enough
            and it is not necessary to build a more detailed mask
            ( f.e the bounding rectangle of a text ).
          */
@@ -77,7 +77,7 @@ public:
            Sometimes it is not possible to give a fast approximation
            and the mask needs to be calculated by drawing the overlay
            and testing the result.
-          
+
            When a valid maskHint() is available
            only pixels inside this approximation are checked.
          */