/*!

\page dependency_tree_page Dependency Tree

\n In order to better understand the relations between the %GEOM 
objects in a study the user has the possibility to display the 
ascendants and descendant of an object in a family tree.

User can build the dependency tree with new main objects by selecting 
them in Object Browser, in OCC Viewer or in Dependency Tree Viewer 
and calling corresponding popup menu. When invoked, this menu item 
will open a 2D view window and display a dependency tree for the 
selected object or objects (multiple selection is supported).

\image html tree_example.png

User can change all necessary parameters of Dependency Tree Viewer 
in \ref pref_dependency_tree "Preferences".

<hr>
\anchor dependency_tree_nodes <h2>Nodes</h2>

Tree nodes in the Dependency Viewer are named according to the study 
names of the corresponding objects. 

Non-published objects are shown in the tree as "unpublished" and are 
colored in special for non-published objects color.

The long name of the object is displayed in a shortened version; 
full name of the object can be seen in the tool tip when the cursor 
is on the node.

Dependency Tree Viewer supports the following states of nodes:

\image html tree_main_node.png
<ul><li><b>Main node</b> - node of main object, selected in Object 
Browser, OCC Viewer or Dependency Tree Viewer in order to build the 
dependency tree;</li></ul>

\image html tree_default_node.png
<ul><li><b>Default node</b> - node, which participate in building of 
dependency tree as ascendant or descendant;</li></ul>

\image html tree_unpublished_node.png
<ul><li><b>Unpublished node</b> - node of non-published in study 
object;</li></ul>

\image html tree_highlighted_node.png
<ul><li><b>Highlighted node</b> - the state of node when mouse is 
near or on it;</li></ul>

\image html tree_selected_node.png
<ul><li><b>Selected node</b> - the state of selected node when 
clicking left mouse button on node.</li></ul>

<hr>
\anchor dependency_tree_links <h2>Links</h2>

Dependency Tree Viewer shows oriented links between nodes to 
represent dependency direction. Viewer supports the following states 
of links:

\image html tree_unidir_link.png
<ul><li><b>Unidirectional link</b> - shows that object A depends on 
the object B;</li></ul>

\image html tree_bidir_link.png
<ul><li><b>Bidirectional link</b> - shows that object A depends on 
the object B and at the same time object B depends on 
the object A;</li></ul>

\image html tree_selfdep_link.png
<ul><li><b>Self-dependency link</b> - shows that object depends on 
itself;</li></ul>

\image html tree_cycldep_link.png
<ul><li><b>Cyclic dependency links</b> - shows cyclic dependency of 
some nodes.</li></ul>

<hr>
\anchor dependency_tree_operations <h2>Operations</h2>

The dependency tree of a chosen %GEOM object is displayed in 
the dedicated 2D view window.
\n The functionalities of 2D viewer are available via its Viewer 
Toolbar. 

Buttons marked with small downward triangles have extended 
functionality which can be accessed by locking on them with left 
mouse button.

\image tree_tool_bar

\image html tree_view_dump.png

<b>Dump View</b> - exports an object from the viewer in bmp, png or
jpeg image format.

\image html tree_view_fitall.png

<b>Fit all</b> - scales the presentation so that it could fit within
the Viewer boundaries.

\image html tree_view_fitarea.png

<b>Fit area</b> - resizes the view to place in the visible area only
the contents of a frame drawn with pressed left mouse button.

\image html tree_view_fitselect.png

<b>Fit selection</b> - resizes the view to fit in the visible area
only currently selected objects.

\image html tree_view_zoom.png

<b>Zoom</b> - allows to zoom in and out.

\image html tree_view_pan.png

<b>Panning</b> - if the represented objects are greater that the
visible area and you don't wish to use <b>Fit all</b> functionality,
click on this button and you'll be able to drag the scene to see its
remote parts.

\image html tree_view_glpan.png

<b>Global panning</b> - allows to select a point to be the center of
the presentation showing all displayed objects in the visible ares.

\image html tree_hierarchy_type.png

<b>Hierarchy depth</b> - allows to change the number of hierarchy 
levels to be shown in the dependency tree.
<ul>
<li>Level 1 corresponds to the parents and children of the selected 
object(s);</li>
<li>Level 2 is Level 1 plus the grand-parents and grand-children 
of the selected object(s);</li>
<li>etc...</li>
</ul>

\image html tree_disp_ascendants.png

<b>Display ascendants</b> - allows to customize the display 
of ascendants.

\image html tree_disp_descendants.png

<b>Display descendants</b> - allows to customize the display 
of descendants.

\image html tree_move_nodes.png

<b>Move nodes</b> - allows to customize the moving of nodes.

\image html tree_button_update.png

<b>Update</b> - allows to update a dependency tree model and a view.

<hr>
\anchor dependency_tree_navigation <h2>Navigation</h2>

Dependency Tree 2D Viewer supports the following navigation mode:

Rectangle selection in this mode is performed by the left mouse 
button; multiple selection is available when \b Shift button 
is pressed.

Also, holding \b Ctrl key with pressed mouse buttons performs 
the following view transformations:
<ul>
<li>Ctrl + left mouse button - zooming;</li>
<li>Ctrl + middle mouse button - panning;</li>
</ul>

<hr>
\anchor dependency_tree_popup_menu <h2>Popup Menu</h2>

After the object has appeared in the Dependency Tree 2D Viewer, 
you can select it with left mouse click to change its presentation 
parameters and access to other useful options by right-clicking on 
the selected object.

\image html tree_popup_menu.png

<ul>
<li>\b Show - allows to show selected object(s) in OCC 3D Viewer;</li>
<li><b> Show Only</b> - allows to show only selected object(s) 
in OCC 3D Viewer;</li>
<li><b> Rebuild the tree</b> - allows to rebuild the dependency tree 
for selected object(s);</li>
</ul>

Some functionalities are available through right-clicking on 
the viewer background:

\image html tree_popup_menu2.png

Dependency Tree 2D Viewer background can be customized using the 
"Change background" popup menu command that opens standard 
"Select Color" dialog box:

\image html selectcolor.png

*/