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LayerManager Class Reference

The LayerManager is used to make changes to layers in the document tree. It holds a pointer to a current spread, and a list of layer details for the current spread (LyrDetLst). The layerDlg and InfoBar make changes to layers in the current spread indirectly by changing the LyrDetList. Layer changes are deferred until the CommitLayerChanges() method is called. Changes made to the LyrDetList can also be cancelled by calling the CancelLayerChanges() method. More...

#include <layermgr.h>

Inheritance diagram for LayerManager:

CCObject SimpleCCObject List of all members.

Public Member Functions

 LayerManager ()
 LayerManager Constructor, initially the LayerManager has no CurrentSpread.
 ~LayerManager ()
 LayerManager destructor.
String_256 CreateUniqueLayerID ()
 Used to generate a LayerID which is unique for the current spread. The name generated is normally of the form "Layer n", where n is the number of layers in the LyrDetList + 1. If "Layer n" already exists on the current spread then "Layer m" is generated where m is the smallest integer greater than n such that the id is unique.
BOOL CommitLayerChanges ()
 If the layer details have changed then performs a LayerChangeOp which modifies the Camelot tree to reflect the changes made to the LyrDetList.
BOOL NewCurrentSpread (Spread *NewCurrentSpread)
 Sets a new current spread.
Spread * GetCurrentSpread ()
 For finding the current spread.
BOOL CancelLayerChanges ()
 This private function gets called from NewCurrentSpread. It informs all subsystems (that need to know) that the Current Spread has changed. The LyrDetList contains the new current spread's details before this function is called. Causes the changes made to the LyrDetList to be discarded, and new values read.
BOOL RefreshLayerDetails ()
 Reads in new layer details and updates the interface.
void UpdateInterface ()
 Updates the interface after layers have changed.

Public Attributes

List LyrDetList

Private Member Functions

void DeleteLayerDetList ()
 Deletes the contents of the LyrDetList.
BOOL ReadSpreadLayerDetails ()
 Read the current spread's layer details into the LyrDetList. If memory runs out then InformError is called and FALSE is returned.
void BroadcastNewCurrentSpread ()
BOOL LayerDetailsChanged ()
 This function compares the current spread's layers against the Layer details list. If the layers have changed in any way, then the function returns TRUE. Otherwise the function returns FALSE.

Private Attributes

Spread * CurrentSpread

Detailed Description

The LayerManager is used to make changes to layers in the document tree. It holds a pointer to a current spread, and a list of layer details for the current spread (LyrDetLst). The layerDlg and InfoBar make changes to layers in the current spread indirectly by changing the LyrDetList. Layer changes are deferred until the CommitLayerChanges() method is called. Changes made to the LyrDetList can also be cancelled by calling the CancelLayerChanges() method.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
7/1/94
See also:
LyrDetails

LayerDlg

OpLayerChange

Definition at line 177 of file layermgr.h.

Constructor & Destructor Documentation

LayerManager::LayerManager (   ) 
 

LayerManager Constructor, initially the LayerManager has no CurrentSpread.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
-

Errors: -

See also:
-

Definition at line 170 of file layermgr.cpp.

00171 {
00172     CurrentSpread = NULL; // There is no current spread 
00173 }

LayerManager::~LayerManager (   ) 
 

LayerManager destructor.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
-

Errors: -

See also:
-

Definition at line 190 of file layermgr.cpp.

00191 {
00192     DeleteLayerDetList(); // Delete the layer details list  
00193 }

Member Function Documentation

void LayerManager::BroadcastNewCurrentSpread (   )  [private]
 

BOOL LayerManager::CancelLayerChanges (   ) 
 

This private function gets called from NewCurrentSpread. It informs all subsystems (that need to know) that the Current Spread has changed. The LyrDetList contains the new current spread's details before this function is called. Causes the changes made to the LyrDetList to be discarded, and new values read.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
TRUE if successful, FALSE otherwise

Errors: If memory runs out then InformError is called and the function returns FALSE

See also:
-

Definition at line 443 of file layermgr.cpp.

00444 {
00445     DeleteLayerDetList();     // Delete details including any changes whioch may have been made
00446     if (ReadSpreadLayerDetails()) // Read new values 
00447     {
00448         return TRUE; 
00449     }
00450     else 
00451     {
00452         return FALSE; 
00453     }
00454 }

BOOL LayerManager::CommitLayerChanges (   ) 
 

If the layer details have changed then performs a LayerChangeOp which modifies the Camelot tree to reflect the changes made to the LyrDetList.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
Returns TRUE if successful, else InformError gets called and FALSE returned.

Errors: -

See also:
-

Definition at line 290 of file layermgr.cpp.

00291 {
00292     if (LayerDetailsChanged()) // The layer details have changed so we need to perform 
00293                                // a LayerChangeOp to commit the changes.  
00294     {
00295         // Invoke the layer change operation 
00296         // Obtain a pointer to the op descriptor for the Layer change operation 
00297         OpDescriptor* OpDesc = 
00298             OpDescriptor::FindOpDescriptor(CC_RUNTIME_CLASS(OpLayerChange)); 
00299         // Invoke the operation. 
00300         OpDesc->Invoke();
00301     }
00302     if (RefreshLayerDetails()) // We need to refresh the layer details even if the layers were 
00303                                // not changed because a new layer could have been deleted  
00304     {
00305         return TRUE; 
00306     }
00307     else return FALSE; // Failed to refresh layer details (InformError has been called)
00308 }

String_256 LayerManager::CreateUniqueLayerID (   ) 
 

Used to generate a LayerID which is unique for the current spread. The name generated is normally of the form "Layer n", where n is the number of layers in the LyrDetList + 1. If "Layer n" already exists on the current spread then "Layer m" is generated where m is the smallest integer greater than n such that the id is unique.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
A LayerID which is unique for the current spread.

Errors: -

See also:
-

Definition at line 214 of file layermgr.cpp.

00215 {
00216     // We can't generate a unique id if there is no current spread 
00217     ENSURE(CurrentSpread != NULL, "There is no current spread"); 
00218 
00219     String_256 UniqueLayerID; 
00220     INT32 NumLayers = 0; 
00221 
00222     ListItem* Lyr = LyrDetList.GetHead(); 
00223 
00224     // Calculate how many layers are on the current spread, we must ignore layers 
00225     // which have been deleted. 
00226     while (Lyr != NULL)
00227     {
00228         if (!((LyrDetails*)Lyr)->Deleted)    // Don't count deleted layers 
00229         {
00230             NumLayers++;    
00231         }
00232         Lyr = LyrDetList.GetNext(Lyr); 
00233     }
00234 
00235     ENSURE(NumLayers != 0, "The current spread has no layers"); 
00236 
00237 
00238     INT32 NewLayerNum = NumLayers+1; 
00239 
00240     BOOL Unique;  // Flag used to indicate if the id generated is unique or not 
00241     do 
00242     {
00243         // Construct a first attempt at a unique layer id 'Layer n' 
00244         // where n = the number of layers on the current spread + 1
00245      
00246         UniqueLayerID.MakeMsg(_R(IDS_LAYERMGR_LAYERNAME),NewLayerNum);   
00247     
00248         // Check that UniqueLayerID is indeed unique 
00249         Unique = TRUE; // Until we know better 
00250         Lyr = LyrDetList.GetHead(); 
00251         while (Lyr != NULL)
00252         {   
00253             if (!((LyrDetails*)Lyr)->Deleted)   // Ignore deleted layers 
00254             {
00255                 if (UniqueLayerID == ((LyrDetails*)Lyr)->Status.StringLayerID)
00256                 {
00257                     Unique = FALSE; 
00258 
00259                     // UniqueLayerID is not unique so increment NewLayerNum and try again 
00260                     NewLayerNum++;      
00261                     break; 
00262                 }
00263             }
00264             Lyr = LyrDetList.GetNext(Lyr); // Get the next layer  
00265         }
00266         
00267     } while (!Unique); 
00268     return(UniqueLayerID); 
00269 }

void LayerManager::DeleteLayerDetList (   )  [private]
 

Deletes the contents of the LyrDetList.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
-

Errors: - Scope: private

See also:
-

Definition at line 500 of file layermgr.cpp.

00501 { 
00502     // Delete all current spread details 
00503     ListItem* Current = LyrDetList.GetHead(); 
00504     while (Current != NULL)
00505     {
00506         delete (LyrDetList.RemoveItem(Current)); 
00507         Current = LyrDetList.GetHead(); 
00508     }                
00509 }

Spread * LayerManager::GetCurrentSpread (   ) 
 

For finding the current spread.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
18/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
The LayerManagers current spread

Errors: -

See also:
-

Definition at line 367 of file layermgr.cpp.

00368 {
00369     return CurrentSpread; 
00370 }

BOOL LayerManager::LayerDetailsChanged (   )  [private]
 

This function compares the current spread's layers against the Layer details list. If the layers have changed in any way, then the function returns TRUE. Otherwise the function returns FALSE.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
21/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
TRUE if the LayerDetails list has changed
Scope: private
Returns:
Errors: -
See also:
-

Definition at line 580 of file layermgr.cpp.

00581 {
00582     LyrDetails* CurrentLyrDet = (LyrDetails*)LyrDetList.GetHead();    
00583     Layer* CurrentLyr = CurrentSpread->FindFirstLayer(); // Get the first layer node 
00584     
00585     ENSURE(CurrentLyrDet != NULL, "There are no layer details on the layer details list"); 
00586     ENSURE(CurrentLyr != NULL, "The LayerManager's current spread has no layers"); 
00587     
00588     while (CurrentLyrDet != NULL) 
00589     {
00590         // We ignore deleted new layers because they don't change anything 
00591         if (!(CurrentLyrDet->New && CurrentLyrDet->Deleted))    
00592         {       
00593             if (CurrentLyr != CurrentLyrDet->m_pLayer) // z-order change 
00594             {
00595                 return TRUE; 
00596             }                                   
00597             else if ((CurrentLyrDet->New) || (CurrentLyrDet->Deleted)) 
00598             {
00599                 return TRUE; // New layer created or existing layer deleted 
00600             }
00601             else if (!(CurrentLyrDet->Status == CurrentLyr->GetLayerStatus()))
00602             {   
00603                 // The layer's status has changed 
00604                 return TRUE; 
00605             }  
00606             CurrentLyrDet =  (LyrDetails*)(LyrDetList.GetNext(CurrentLyrDet));
00607             CurrentLyr = (CurrentLyr->FindNextLayer()); 
00608         }   
00609         else    
00610             CurrentLyrDet = (LyrDetails*)(LyrDetList.GetNext(CurrentLyrDet)); 
00611     }      
00612     // Sanity check 
00613     ENSURE (CurrentLyr == NULL, "CurrentLyr ptr should be NULL"); 
00614     return FALSE; // Nothing has changed    
00615 }

BOOL LayerManager::NewCurrentSpread (  Spread *  NewCurrentSpread  ) 
 

Sets a new current spread.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
NewCurrentSpread [INPUTS]
- [OUTPUTS]
Returns:
TRUE if successful, else FALSE

Errors: InformError gets called and FALSE is returned if we run out of memory

See also:
-

Definition at line 326 of file layermgr.cpp.

00327 {
00328     ENSURE(NewCurrentSpread != NULL, "The new current spread is NULL"); 
00329     BOOL ok = TRUE;
00330     
00331     if (CurrentSpread != NULL)  // There is already a current spread 
00332     {
00333         
00334         // The LayerDetList should never be empty 
00335         ENSURE(!LyrDetList.IsEmpty(), "Empty Layer details list"); 
00336 
00337         DeleteLayerDetList();  
00338     
00339     }
00340     
00341     // The LayerDetList should be empty 
00342     ENSURE(LyrDetList.IsEmpty(), "Empty Layer details list"); 
00343 
00344     CurrentSpread = NewCurrentSpread; 
00345 
00346     // Read the current spread's layer details into the LyrDetList
00347     ok = ReadSpreadLayerDetails();
00348 
00349     return (ok);
00350 }

BOOL LayerManager::ReadSpreadLayerDetails (   )  [private]
 

Read the current spread's layer details into the LyrDetList. If memory runs out then InformError is called and FALSE is returned.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
10/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
TRUE if successful, else FALSE

Errors: - Scope: private

See also:
-

Definition at line 530 of file layermgr.cpp.

00531 {
00532     ENSURE(CurrentSpread != NULL, "Trying to read the details of a NULL current spread"); 
00533     ENSURE(LyrDetList.IsEmpty(), "Layer details list not empty"); 
00534 
00535     LyrDetails* LayerDet; 
00536 
00537     Layer* Current = CurrentSpread->FindFirstLayer(); 
00538     while (Current != NULL) 
00539     {
00540         // Found a layer so record the details 
00541         LayerDet = new LyrDetails(); 
00542         if (LayerDet == NULL)
00543         {
00544             // Inform an error - The error will already be set by new
00545             InformError();
00546             return FALSE; 
00547         }
00548         LayerDet->Status = (Current)->GetLayerStatus(); // record the layer status  
00549         LayerDet->m_pLayer = Current; 
00550         LayerDet->New = FALSE; 
00551         LayerDet->Deleted = FALSE; 
00552 
00553         LyrDetList.AddTail(LayerDet); // Add the layers details to the tail of the layer 
00554                                        // detail list, so preserving the correct z-order. 
00555         Current = Current->FindNextLayer(); 
00556     }
00557     ENSURE(!LyrDetList.IsEmpty(), "No layers found on the current spread"); 
00558     return TRUE; 
00559 }

BOOL LayerManager::RefreshLayerDetails (   ) 
 

Reads in new layer details and updates the interface.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
17/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
Returns TRUE if successful, else calls InformError and returns FALSE

Errors: -

See also:
-

Definition at line 471 of file layermgr.cpp.

00472 {
00473     // Make sure that no changes have been made 
00474     DeleteLayerDetList();     // Delete details including any changes whioch may have been made
00475     if (ReadSpreadLayerDetails()) // Read new values 
00476     {
00477         UpdateInterface();  
00478         return TRUE;    
00479     }
00480     else return FALSE;   // InformError has been called 
00481 }

void LayerManager::UpdateInterface (   ) 
 

Updates the interface after layers have changed.

Author:
Simon_Maneggio (Xara Group Ltd) <camelotdev@xara.com>
Date:
17/1/94
Parameters:
- [INPUTS]
- [OUTPUTS]
Returns:
-

Errors: -

See also:
-

Definition at line 387 of file layermgr.cpp.

00388 {
00389 //  BroadcastNewCurrentSpread(); 
00390 }

Member Data Documentation

Spread* LayerManager::CurrentSpread [private]
 

Definition at line 209 of file layermgr.h.

List LayerManager::LyrDetList
 

Definition at line 206 of file layermgr.h.

The documentation for this class was generated from the following files:
Generated on Sat Nov 10 03:55:45 2007 for Camelot by  doxygen 1.4.4