/*!
-\page common_functionality_page Common functionality
+\page common_functionality_page Functionality common for OCC and VTK viewers
\anchor viewer_background
<h2>Background</h2>
The following types of the background are supported:
-- Single color: the background is colored with the solid color
+- <b> Single color: </b> the background is colored with the solid color
specified by the user in the dialog box.
-- Gradient background: the background is gradiently colored according
+- <b> Gradient background: </b> the background is gradiently colored according
to two colors and the gradient type specified in the dialog box. The
following types of background are supported:
- Fourth corner
-- Image: allows to set image as viewer background and define filling type:
+- \b Image: allows to set image as viewer background and define filling type:
- - Center: the image is located at the center of the viewer backgound
+ - \b Center: the image is located at the center of the viewer backgound
- - Tile: the image fills the entire viewer backgound one by one
+ - \b Tile: the image fills the entire viewer backgound one by one
- - Stretch: the image is stretched to the entire viewer backgound.
+ - \b Stretch: the image is stretched to the entire viewer backgound.
Default background for the OCC viewer is specified via the
\ref occ_preferences "OCC 3D Viewer Preferences" and for the
<h2>Selection</h2>
-For selecting it is necessary to click by left mouse button on the required
-element. Thus, this element will be selected.
+An element can be selected by clicking on it with the left mouse button.
+Selecting objects with locked \em Shift key produces a multi selection.
-Also, holding down the <b>Shift</b> key while selecting objects will
-produce multi selection.
+Additionally, when the viewer owns an input focus, an object can be selected
+by pressing \em "S" on the keyboard. Pressing \em "S" when holding
+\em Shift key allows adding/removing an object to/from the current selection.
-In the viewers there are two mechanism for selecting: rectangle and
+OCC viewer provides a way to navigate between the selectable objects.
+This feature (disabled by default) is used in some dialog boxes (for example,
+in Geometry module). When there are several objects which suit current
+selection requirements (specified by the dialog) under the current mouse cursor,
+it is possible to switch between them by means of mouse scroll wheel.
+The same can be also done by pressing \em "N" and \em "P" keys.
+
+There are also two additional selection mechanisms: rectangle and
polyline selection.
<h3>Rectangle selection</h3>
-The Rectangle Selection tool is designed to select rectangular regions:
-it is the most basic of the selection tools and very commonly used.
+Rectangle Selection is the basic and commonly used selection tool.
-For selecting area by rectangle press left mouse button and draw it on
-the viewer holding down the left mouse button.
-
-To add an area to the existing selection it is necessary to hold down
-<b>Shift</b> key while selecting.
+To select a rectangle area press and hold the left mouse button while drawing the diagonal of the selection rectangle in the viewer.
\image html rectselectionvtk.png
-As a result, only a rectangle is selected.
+
+As a result, the objects within the rectangle are selected.
+
\image html rectselectionvtk2.png
+\note It is possible to add an area to the existing selection by holding down
+\em Shift key while selecting.
+
<h3>Polyline selection</h3>
-OCC and VTK Viewers features a special Polyline Selection mechanism,
-which allows selecting an arbitraty part of the graphic area using a
+OCC and VTK Viewers feature a special Polyline Selection mechanism,
+which allows selecting an arbitrary part of the graphic area using a
polygon frame (rubber band), instead of the usual selection with a
rectangular frame.
-To produce a Polyline Selection, lock the right mouse button and draw
-the first side of the polygon, then change the direction by clicking
-the left mouse button add draw another side, etc. The whole selection
-frame is drawn with the locked right mouse button.
-
-To add an area to the existing selection it is necessary to hold down
-<b>Shift</b> key while selecting.
+To produce a Polyline Selection, press and hold the right mouse button and draw
+the first side of the selection polygon, then change the direction by clicking
+the left mouse button add draw another side, etc. Click twice by left mouse
+button to finish drawing.
\image html polyselectionvtk11.png
-As a result, only the faces within the frame are selected.
+
+As a result, the objects within the polygon are selected.
+
\image html polyselectionvtk21.png
+To add an area to the existing selection it is necessary to hold down
+\em Shift key while selecting.
+
<hr>
\anchor viewer_navigation_modes
- <b>Salome standard controls</b>
- Rectangle selection in this mode is performed by left mouse button,
- polyline selection is done by right mouse button;
- multiple selection is available when \b Shift button is pressed.
+ Rectangle selection in this mode is performed by the left mouse button
+ and polyline selection by the right mouse button;
+ multiple selection is available when \em Shift button is pressed.
- Also, holding \b Ctrl key pressed in conjunction with
- mouse buttons performs view transformations:
- - \b Ctrl + left mouse button - zooming;
- - \b Ctrl + middle mouse button - panning;
- - \b Ctrl + right mouse button - rotation.
+ Also, holding \em Ctrl key with pressed mouse buttons performs the following view transformations:
+ - \em Ctrl + left mouse button - zooming;
+ - \em Ctrl + middle mouse button - panning;
+ - \em Ctrl + right mouse button - rotation.
- <b>Keyboard free style</b>
- This mode allows to process all view transformations without using
- keyboard (only by mouse):
- - \b Left mouse button performs view rotation;
- - \b Middle mouse button performs panning;
- - \b Right mouse button makes zooming.
- .
-
- In this style selection of objects in view is performed by pressing
- "S" key or by left mouse button click. Rectangle selection is done
- by left mouse button when holding \b Ctrl key; polyline selection
- is done by right mouse button with \b Ctrl key pressed.
+ This mode allows performing all view transformations without using the
+ keyboard (only by the mouse):
+ - Left mouse button performs view rotation;
+ - Middle mouse button performs panning;
+ - Right mouse button makes zooming.
+
+ In this style rectangle selection is done by the left mouse button with \em Ctrl key pressed;
+ polyline selection is done by the right mouse button with \em Ctrl key pressed.
+
+In both styles selection of objects in the viewer can be performed by pressing
+\em "S" key or by the left mouse button click.
+
+Zooming can be alternatively done by scrolling mouse wheel.
*/
