[dasher: 206/217] Correctly calculate offset after control box move and delete commands.

[Patrick Welche <pwelche src gnome org>]

commit 5f82c6af7ae639621aa5c49ae046dee4556dc64e
Author: Ada Majorek <amajorek google com>
Date:   Mon Feb 8 11:47:37 2016 -0800

    Correctly calculate offset after control box move and delete commands.
    
    fixeshttps://github.com/ipomoena/dasher/issues/13

 Src/DasherCore/ControlManager.cpp    |   27 +++------------------------
 Src/DasherCore/DasherInterfaceBase.h |   10 ++++++++++
 Src/Win32/Dasher.cpp                 |    4 ++++
 Src/Win32/Dasher.h                   |    1 +
 Src/Win32/Widgets/Edit.cpp           |    7 +++++++
 Src/Win32/Widgets/Edit.h             |    3 ++-
 6 files changed, 27 insertions(+), 25 deletions(-)
---
diff --git a/Src/DasherCore/ControlManager.cpp b/Src/DasherCore/ControlManager.cpp
index d831af6..1d051c6 100644
--- a/Src/DasherCore/ControlManager.cpp
+++ b/Src/DasherCore/ControlManager.cpp
@@ -312,15 +312,8 @@ public:
   int calculateNewOffset(CControlBase::CContNode *pNode, int offsetBefore) override {
     if (m_bForwards)
       return offsetBefore;
-    switch (m_dist) {
-    case CControlManager::EDIT_FILE:
-      return -1;
-    case CControlManager::EDIT_CHAR: {
-      return max(-1, offsetBefore - 1);
-    }
-    default:
-      return offsetBefore;
-    }
+
+    return pNode->mgr()->GetDasherInterface()->ctrlOffsetAfterMove(offsetBefore + 1, m_bForwards, m_dist) - 
1;
   }
   virtual void happen(CControlBase::CContNode *pNode) {
     pNode->mgr()->GetDasherInterface()->ctrlDelete(m_bForwards, m_dist);
@@ -334,21 +327,7 @@ public:
   Move(bool bForwards, CControlManager::EditDistance dist) : m_bForwards(bForwards), m_dist(dist)  {
   }
   int calculateNewOffset(CControlBase::CContNode *pNode, int offsetBefore) override {
-    switch (m_dist) {
-    case CControlManager::EDIT_FILE:
-      return m_bForwards ? pNode->mgr()->GetDasherInterface()->GetAllContextLenght() - 1 : -1;
-
-    case CControlManager::EDIT_CHAR: {
-      if (m_bForwards) {
-        int maxPos = pNode->mgr()->GetDasherInterface()->GetAllContextLenght() - 1;
-        return min(maxPos, offsetBefore + 1);
-      }
-      else
-        return max(-1, offsetBefore - 1);
-    }
-    default:
-      return offsetBefore;
-    }
+    return pNode->mgr()->GetDasherInterface()->ctrlOffsetAfterMove(offsetBefore + 1, m_bForwards, m_dist) - 
1;
   }
   virtual void happen(CControlBase::CContNode *pNode) {
     pNode->mgr()->GetDasherInterface()->ctrlMove(m_bForwards, m_dist);
diff --git a/Src/DasherCore/DasherInterfaceBase.h b/Src/DasherCore/DasherInterfaceBase.h
index 4f90441..ffd9be4 100644
--- a/Src/DasherCore/DasherInterfaceBase.h
+++ b/Src/DasherCore/DasherInterfaceBase.h
@@ -182,6 +182,16 @@ public:
   ///Subclasses supporting clipboard operations should override to copy
   /// the specified text to the clipboard. (Default implementation does nothing).
   virtual void CopyToClipboard(const std::string &text) {}
+ 
+  ///Called to calculate offset after control-mode "move" or delete commands.
+  ///\param bForwards true to move forwards (right), false for backwards
+  ///\param dist how far to move: character, word, line, ..., file. (Usually defined
+  /// by OS, e.g. for non-european languages)
+  ///\return the offset, into the edit buffer where the cursor would be *after* the move.
+  virtual unsigned int ctrlOffsetAfterMove(unsigned int offsetBefore, bool bForwards,
+    CControlManager::EditDistance iDist) {
+    return offsetBefore;
+  }
 
   ///Called to execute a control-mode "move" command.
   ///\param bForwards true to move forwards (right), false for backwards
diff --git a/Src/Win32/Dasher.cpp b/Src/Win32/Dasher.cpp
index 310f4f4..73a5ccc 100644
--- a/Src/Win32/Dasher.cpp
+++ b/Src/Win32/Dasher.cpp
@@ -127,6 +127,10 @@ void Dasher::CDasher::editDelete(const string &strText, CDasherNode *pSource) {
   CDasherInterfaceBase::editDelete(strText, pSource);
 }
 
+unsigned int Dasher::CDasher::ctrlOffsetAfterMove(unsigned int offsetBefore, bool bForwards, 
CControlManager::EditDistance iDist) {
+  return m_pEdit->OffsetAfterMove(offsetBefore, bForwards, iDist);
+}
+
 unsigned int Dasher::CDasher::ctrlMove(bool bForwards, CControlManager::EditDistance iDist) {
   return m_pEdit->Move(bForwards, iDist);
 }
diff --git a/Src/Win32/Dasher.h b/Src/Win32/Dasher.h
index 488c24e..a194a89 100644
--- a/Src/Win32/Dasher.h
+++ b/Src/Win32/Dasher.h
@@ -58,6 +58,7 @@ public:
   void HandleEvent(int iParameter) override;
   void editOutput(const std::string &strText, CDasherNode *pSource) override;
   void editDelete(const std::string &strText, CDasherNode *pSource) override;
+  unsigned int ctrlOffsetAfterMove(unsigned int offsetBefore, bool bForwards, CControlManager::EditDistance 
iDist) override;
   unsigned int ctrlMove(bool bForwards, CControlManager::EditDistance iDist) override;
   unsigned int ctrlDelete(bool bForwards, CControlManager::EditDistance iDist) override;
     
diff --git a/Src/Win32/Widgets/Edit.cpp b/Src/Win32/Widgets/Edit.cpp
index 4cd5c34..b7d0c07 100644
--- a/Src/Win32/Widgets/Edit.cpp
+++ b/Src/Win32/Widgets/Edit.cpp
@@ -434,6 +434,13 @@ std::string CEdit::GetTextAroundCursor(CControlManager::EditDistance iDist) {
   return wstring_to_UTF8string(wideText.Mid(iStart, iEnd-iStart));
 }
 
+unsigned int CEdit::OffsetAfterMove(unsigned int offsetBefore, bool bForwards, CControlManager::EditDistance 
iDist) {
+  int iStart, iEnd;
+  iStart = iEnd = offsetBefore;
+  GetRange(bForwards, iDist, &iStart, &iEnd);
+  return bForwards ? iEnd : iStart;
+}
+
 int CEdit::Move(bool bForwards, CControlManager::EditDistance iDist) {
   int iStart = 0;
   int iEnd = 0;
diff --git a/Src/Win32/Widgets/Edit.h b/Src/Win32/Widgets/Edit.h
index 68138b5..b6cd43f 100644
--- a/Src/Win32/Widgets/Edit.h
+++ b/Src/Win32/Widgets/Edit.h
@@ -76,7 +76,8 @@ class CEdit : public ATL::CWindowImpl<CEdit> {
 
 
   void Move(int x, int y, int Width, int Height);
-       
+
+  unsigned int OffsetAfterMove(unsigned int offsetBefore, bool bForwards,  
Dasher::CControlManager::EditDistance iDist);
   int Move(bool bForwards, Dasher::CControlManager::EditDistance iDist);
   int Delete(bool bForwards, Dasher::CControlManager::EditDistance iDist);
   std::string GetTextAroundCursor(Dasher::CControlManager::EditDistance iDist);