[dasher: 4/27] Keep same DasherModel when NodeCreationManager changes & just rebuild nodes.

[Patrick Welche <pwelche src gnome org>]

commit 326da47b5c6a699ed32c13dc91d04cdd6d326192
Author: Alan Lawrence <acl33 inf phy cam ac uk>
Date:   Wed Aug 4 18:29:38 2010 +0100

    Keep same DasherModel when NodeCreationManager changes & just rebuild nodes.
    
    CDasherInterfaceBase::SetOffset has extra bool param, passes to CDasherModel;
    default is false, but SetBuffer == SetOffset(...,true).

 Src/DasherCore/DasherInterfaceBase.cpp  |   72 ++++++++++++------------------
 Src/DasherCore/DasherInterfaceBase.h    |   22 ++++++++--
 Src/iPhone/Classes/DasherAppDelegate.mm |    5 +-
 3 files changed, 50 insertions(+), 49 deletions(-)
---
diff --git a/Src/DasherCore/DasherInterfaceBase.cpp b/Src/DasherCore/DasherInterfaceBase.cpp
index 2626e2e..000066f 100644
--- a/Src/DasherCore/DasherInterfaceBase.cpp
+++ b/Src/DasherCore/DasherInterfaceBase.cpp
@@ -130,6 +130,10 @@ CDasherInterfaceBase::CDasherInterfaceBase() {
 void CDasherInterfaceBase::Realize() {
   // TODO: What exactly needs to have happened by the time we call Realize()?
   CreateSettingsStore();
+
+  //create the model... (no nodes just yet)
+  m_pDasherModel = new CDasherModel(m_pEventHandler, m_pSettingsStore, this);
+
   SetupUI();
   SetupPaths();
 
@@ -165,7 +169,12 @@ void CDasherInterfaceBase::Realize() {
   CreateInput();
   CreateInputFilter();
   
-  ChangeAlphabet(); // This creates the NodeCreationManager, the Alphabet
+  ChangeAlphabet(); // This creates the NodeCreationManager, the Alphabet,
+  //and the tree of nodes in the model. Now we can
+  // Notify the teacher of the new model...ACL TODO pending merging of new
+  // game mode code; when Ryan's stuff arrives we can delete this:
+  if(GameMode::CDasherGameMode* pTeacher = GameMode::CDasherGameMode::GetTeacher())
+    pTeacher->SetDasherModel(m_pDasherModel);
 
   SetupActionButtons();
   CParameterNotificationEvent oEvent(LP_NODE_BUDGET);
@@ -377,49 +386,26 @@ void CDasherInterfaceBase::WriteTrainFilePartial() {
   strTrainfileBuffer = strTrainfileBuffer.substr(100);
 }
 
-void CDasherInterfaceBase::CreateModel(int iOffset) {
-  // Creating a model without a node creation manager is a bad plan
-  if(!m_pNCManager)
-    return;
-
-  delete m_pDasherModel;
-  
-  // TODO: Eventually we'll not have to pass the NC manager to the model...(?)
-  m_pDasherModel = new CDasherModel(m_pEventHandler, m_pSettingsStore, this);
-  m_pDasherModel->SetOffset(iOffset, m_pNCManager->GetAlphabetManager(), m_pDasherView, true);
-
-  // Notify the teacher of the new model
-  if(GameMode::CDasherGameMode* pTeacher = GameMode::CDasherGameMode::GetTeacher())
-    pTeacher->SetDasherModel(m_pDasherModel);
-
-}
-
 void CDasherInterfaceBase::CreateNCManager() {
-  // TODO: Try and make this work without necessarilty rebuilding the model
 
-  if(!m_AlphIO)
+  if(!m_AlphIO || GetLongParameter(LP_LANGUAGE_MODEL_ID)==-1)
     return;
 
-  int lmID = GetLongParameter(LP_LANGUAGE_MODEL_ID);
+  //can't delete the old manager yet until we've deleted all its nodes...
+  CNodeCreationManager *pOldMgr = m_pNCManager;
 
-  if( lmID == -1 )
-    return;
+  //now create the new manager...
+  m_pNCManager = new CNodeCreationManager(this, m_pEventHandler, m_pSettingsStore, m_AlphIO);
 
-  //0 seems the right offset if we don't have a model (=at startup)...
-  int iOffset = m_pDasherModel ? m_pDasherModel->GetOffset() : 0;
+  m_Alphabet = m_pNCManager->GetAlphabet();
 
-    // Delete the old model and create a new one
-    // (must delete model first, as its nodes refer to NodeManagers inside the NCManager)
-  delete m_pDasherModel; m_pDasherModel = NULL;
+  //and start a new tree of nodes from it (retaining old offset -
+  // this will be a sensible default of 0 if no nodes previously existed).
+  // This deletes the old tree of nodes... 
+  m_pDasherModel->SetOffset(m_pDasherModel->GetOffset(), m_pNCManager->GetAlphabetManager(), m_pDasherView, true);
 
-  delete m_pNCManager;
-
-    m_pNCManager = new CNodeCreationManager(this, m_pEventHandler, m_pSettingsStore, m_AlphIO);
-
-    m_Alphabet = m_pNCManager->GetAlphabet();
-
-    // TODO: Eventually we'll not have to pass the NC manager to the model...
-    CreateModel(iOffset);
+  //...so now we can delete the old manager
+  delete pOldMgr;
 }
 
 CDasherInterfaceBase::TextAction::TextAction(CDasherInterfaceBase *pIntf) : m_pIntf(pIntf) {
@@ -1131,14 +1117,14 @@ void CDasherInterfaceBase::ChangeState(ETransition iTransition) {
   }
 }
 
-void CDasherInterfaceBase::SetBuffer(int iOffset) {
-   CreateModel(iOffset);
-}
+void CDasherInterfaceBase::SetOffset(int iOffset, bool bForce) {
+  std::cout << "DasherIntf::SetOffset(" << iOffset << "," << bForce << ")" << std::endl;
+  m_pDasherModel->SetOffset(iOffset, m_pNCManager->GetAlphabetManager(), m_pDasherView, bForce);
+  //ACL TODO note that CTL_MOVE, etc., do not come here (that would probably
+  // rebuild the model / violently repaint the screen every time!). But we
+  // still want to notifyOffset all text actions, so the "New" suboption sees
+  // all the editing the user's done...
 
-void CDasherInterfaceBase::SetOffset(int iOffset) {
-  if(m_pDasherModel)
-    m_pDasherModel->SetOffset(iOffset, m_pNCManager->GetAlphabetManager(), m_pDasherView, false);
-  //ACL TODO FIXME check that CTL_MOVE, etc., eventually come here?
   for (set<TextAction *>::iterator it = m_vTextActions.begin(); it!=m_vTextActions.end(); it++) {
     (*it)->NotifyOffset(iOffset);
   }
diff --git a/Src/DasherCore/DasherInterfaceBase.h b/Src/DasherCore/DasherInterfaceBase.h
index cc94d88..868015c 100644
--- a/Src/DasherCore/DasherInterfaceBase.h
+++ b/Src/DasherCore/DasherInterfaceBase.h
@@ -279,16 +279,30 @@ public:
   /// \param iOffset Document me
   //  int TrainFile(std::string Filename, int iTotalBytes, int iOffset);
 
-  /// Set the context in which Dasher makes predictions
-  /// \param strNewContext The new context (UTF-8)
+  /// Part of the mechanism by which the DasherCore part gets the surrounding
+  /// (preceding) characters from its context (i.e. the text edit box): an
+  /// EV_EDIT_CONTEXT_REQUEST event specifying the context required (i.e.
+  /// offset and length) is broadcast from the core, and picked up
+  /// by platform-dependent code, which must then call SetContext with the
+  /// requested text. TODO this is a ghastly mechanism: the
+  /// EditContextRequest event goes to every component, and any number (>=0)
+  /// of components (anywhere!) could call SetContext (at any time!), rather
+  /// than just exactly one, _only_ in response to such an event...suggest
+  /// sthg like "virtual std::string getContext(int off, int len)=0;" ???
+  /// \param strNewContext The requested part of the context (UTF-8)
 
   void SetContext(std::string strNewContext);
 
   /// New control mechanisms:
 
-  void SetBuffer(int iOffset);
+  ///Equivalent to SetOffset(iOffset, true)
+  void SetBuffer(int iOffset) {SetOffset(iOffset, true);}
 
-  void SetOffset(int iOffset);
+  /// Tells the model to rebuild itself with the
+  /// cursor at the specified offset (position within textbox/buffer).
+  /// @param bForce true meaning the entire context may have changed,
+  /// false if we've just moved around within it.
+  void SetOffset(int iOffset, bool bForce=false);
 
   /// @name Status reporting
   /// Get information about the runtime status of Dasher which might
diff --git a/Src/iPhone/Classes/DasherAppDelegate.mm b/Src/iPhone/Classes/DasherAppDelegate.mm
index affd253..c9acb83 100644
--- a/Src/iPhone/Classes/DasherAppDelegate.mm
+++ b/Src/iPhone/Classes/DasherAppDelegate.mm
@@ -276,7 +276,7 @@
 - (void)clearText {
   text.text=@"";
   selectedText.location = selectedText.length = 0;
-  _dasherInterface->SetBuffer(0);
+  _dasherInterface->SetOffset(0);
 }
 	
 - (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {
@@ -354,7 +354,8 @@
 
 - (void)insertText:(NSString *)sText {
   [self outputCallback:sText];
-  _dasherInterface->SetOffset(selectedText.location);
+  // if any text, it came from outside, so buffer/context has changed
+  _dasherInterface->SetOffset(selectedText.location, [sText length]);
 }
 
 - (void)applicationWillResignActive:(UIApplication *)application {