uiODMain

OpendTect Top Level. More...

Classes
class	ArrowSubItem
class	dgbODSessionTranslator
class	ImageSubItem
class	Line2DTreeItemFactory
class	MeasureToolMan
class	ODSession
	dTect session save/restore More...
class	ODSessionTranslator
class	ODSessionTranslatorGroup
class	ScaleBarSubItem
class	uiODSceneMgr::Scene
class	uiFaultStickTransferDlg::Setup
class	VolProc::uiDataTreeItem
class	uiFaultStickTransferDlg
class	uiFirewallProcSetter
class	uiHostIDDlg
class	uiKeyBindingSettingsGroup
class	uiOD2DLineSetAttribItem
class	uiOD2DLineTreeItem
class	uiODAnnotParentTreeItem
class	uiODAnnotSubItem
class	uiODAnnotTreeItem
class	uiODAnnotTreeItemFactory
class	uiODApplMgr
	Application level manager - ties part servers together. More...
class	uiODApplMgrAttrVisHandler
	Does visualization-related work for uiODApplMgr. More...
class	uiODApplMgrDispatcher
	Dispatches work for Appl Mgr. More...
class	uiODApplService
	uiApplService for OD More...
class	uiODAttribTreeItem
class	uiODBodyDisplayDataTreeItem
class	uiODBodyDisplayParentTreeItem
class	uiODBodyDisplayTreeItem
class	uiODBodyDisplayTreeItemFactory
class	uiODCrosslineParentTreeItem
class	uiODCrosslineTreeItem
class	uiODCrosslineTreeItemFactory
class	uiODDataTreeItem
class	uiODDisplayTreeItem
class	uiODEarthModelSurfaceDataTreeItem
class	uiODEarthModelSurfaceTreeItem
class	uiODEditAttribColorDlg
class	uiODFaultParentTreeItem
class	uiODFaultStickSetParentTreeItem
class	uiODFaultStickSetTreeItem
class	uiODFaultStickSetTreeItemFactory
class	uiODFaultSurfaceDataTreeItem
class	uiODFaultToolMan
class	uiODFaultTreeItem
class	uiODFaultTreeItemFactory
class	uiODHelpMenuMgr
	The OpendTect help menu manager. More...
class	uiODHorizon2DParentTreeItem
class	uiODHorizon2DTreeItem
class	uiODHorizon2DTreeItemFactory
class	uiODHorizonParentTreeItem
class	uiODHorizonTreeItem
class	uiODHorizonTreeItemFactory
class	uiODInlineParentTreeItem
class	uiODInlineTreeItem
class	uiODInlineTreeItemFactory
class	uiODLangMenuMgr
	The OpendTect language menu manager. More...
class	uiODLine2DParentTreeItem
class	uiODMain
	OpendTect application top level object. More...
class	uiODMenuMgr
	The OpendTect menu manager. More...
class	uiODParentTreeItem
class	uiODPickSetParentTreeItem
class	uiODPickSetTreeItem
class	uiODPickSetTreeItemFactory
class	uiODPlaneDataTreeItem
class	uiODPolygonParentTreeItem
class	uiODPolygonTreeItem
class	uiODPolygonTreeItemFactory
class	uiODPSEventsParentTreeItem
class	uiODPSEventsTreeItem
class	uiODPSEventsTreeItemFactory
class	uiODRandomLineParentTreeItem
class	uiODRandomLineTreeItem
class	uiODRandomLineTreeItemFactory
class	uiODSceneMgr
	Manages the scenes and the corresponding trees. More...
class	uiODSceneTreeItem
class	uiODTreeItem
class	uiODTreeItemFactory
class	uiODTreeTop
class	uiODViewer2D
	A 2D Viewer. More...
class	uiODViewer2DMgr
class	uiODViewer2DPosDlg
class	uiODViewer2DPosGrp
class	uiODVolrenAttribTreeItem
class	uiODVolrenParentTreeItem
class	uiODVolrenSubTreeItem
class	uiODVolrenTreeItem
class	uiODVolrenTreeItemFactory
class	uiODVw2DFaultParentTreeItem
class	uiODVw2DFaultSS2DParentTreeItem
class	uiODVw2DFaultSS2DTreeItem
class	uiODVw2DFaultSS2DTreeItemFactory
class	uiODVw2DFaultSSParentTreeItem
class	uiODVw2DFaultSSTreeItem
class	uiODVw2DFaultSSTreeItemFactory
class	uiODVw2DFaultTreeItem
class	uiODVw2DFaultTreeItemFactory
class	uiODVw2DHor2DParentTreeItem
class	uiODVw2DHor2DTreeItem
class	uiODVw2DHor2DTreeItemFactory
class	uiODVw2DHor3DParentTreeItem
class	uiODVw2DHor3DTreeItem
class	uiODVw2DHor3DTreeItemFactory
class	uiODVw2DPickSetParentTreeItem
class	uiODVw2DPickSetTreeItem
class	uiODVw2DPickSetTreeItemFactory
class	uiODVw2DTreeItem
class	uiODVw2DTreeItemFactory
class	uiODVw2DTreeTop
class	uiODVW2DVariableDensityTreeItem
class	uiODVW2DVariableDensityTreeItemFactory
class	uiODVW2DWiggleVarAreaTreeItem
class	uiODVW2DWiggleVarAreaTreeItemFactory
class	uiODWellParentTreeItem
class	uiODWellTreeItem
class	uiODWellTreeItemFactory
class	uiODZsliceParentTreeItem
class	uiODZsliceTreeItem
class	uiODZsliceTreeItemFactory
class	uiPluginInitMgr
class	uiServiceClientMgr
class	uiSessionMan
	Session manager. More...

Detailed Description

OpendTect Top Level.

Introduction

'Real systems have no top' (Betrand Meyer). What he meant is that real sytems cannot be characterised by a single function which can be split up into smaller functions and so on - the classical functional decomposition problem. Still, Object-oriented systems tend to have a top - a top level object containing or initiating the work.

In OpendTect, this object is of the class uiODMain. There is one instance which is accessible through the global function ODMainWin().

If you go down the responsibility graph from here you will find yourself in the world of the 'Application Logic'. This is software with the sole purpose of making this application do its work. In OO systems, as much intelligence and functionality needs to be put in general-purpose objects. In that sense, the usage of application logic objects needs to be minimised, and generalised objects re-usable in other applications should be preferred.

OpendTect obeys that rule but still a considerable amount of application-specific coding is unavoidable, especially in the area of the user interface. And in larger systems things get out of hand in no time because of the complexity of the task to manage everything. Therefore, we designed some 'complexity-stoppers'. The trouble with those kind of objects is that they themselves make it harder to understand what's going on in the system. It is much easier to understand:

"object A uses object B and C and then displays using D."

than:

"object A asks its service manager S that it needs input data. S asks B and C for the data and passes it to A. A does its thing and reports S it's ready. S then asks D to display the data it asks from A."

In reality it's even worse than this. We wouldn't have done that if OpendTect were a nice little app of a few thousand lines of code. That is not the case. In larger systems dependency management is the name of the game. It becomes important to figure out what object 'knows' about what other objects and who is responsible for what. Further it becomes increasingly important to not only hide low-level details from high-level functionality, but also to make them independent of it. This is the foundation of the 'Dependency Inversion' principle. In the overview of the Programmer's manual you will see a reference to documentation on this.

Content

As things are, two major things need to be introduced: the top-level manager objects and their responsibilities, and the 'Part Server' architecture.

First of all, the top-level manager objects. This is fairly straightforward. The application level problems are foremost:

• managing the menu and tool buttons
• managing the scenes and related trees of user objects
• doing the things that need to be done
• color table and other 'rest' things

All these things are uiODMain's responsibilities. The last item is done 'directly' by uiODMain (of course it uses some fairly high level objects to do that, but still). The first three are delegated to three closely cooperating manager objects: uiODMenuMgr, uiODSceneMgr, and uiODApplMgr .

To go to the second issue we'll ask the question: how does the application manager (the uiODApplMgr instance) get things done? Answer: it asks its 'Part Manager' objects to do the work. The only thing uiODApplMgr does is coordinate everything. The next question then is: what is such a 'Part Manager'? Answer: an object providing services for a certain type of things needed in OpendTect.

Example: The menu manager finds out that the user wants to do attribute editing (probably a menu item or button was clicked). The menu manager asks the application manager to take care of that. The application manager knows this is Attribute stuff, so it uses its uiAttribPartServer instance: it calls the editSet() method. During the editing however, the attrib part server may need data or services that are not strictly 'attribute' stuff. For example, when the user presses 'direct display' of attribute the attrib part server must know where to calculate the current attribute and it needs to deliver the data when finished.

When a part server needs external data or when it has info that may be important for other part servers, it calls the 'sendEvent()' method to notify (via its 'uiApplService' instance) the application manager. In this case the application manager will then ask its uiVisPartServer instance about the position of the current element.

Part servers are an absolute must to keep the complexity on the application level manageable. Already things are pretty complex; if all objects would 'know' about all other objects things would get out of hand very quickly to the point that lots of bugs are very hard to solve and maintenance would be a nightmare.