Introduce SharedSolver class to improve BALMLayout's friend feature.

headers/libs/alm/ALMLayout.h

@@ -17,6 +17,10 @@
 class BView;
 class BLayoutItem;
 
+namespace BPrivate {
+	class SharedSolver;
+};
+
 
 namespace BALM {
 
@@ -157,6 +161,7 @@ private:
 
 	template <class T>
 	friend class TabAddTransaction;
+	friend class BPrivate::SharedSolver;
 
 	friend class XTab;
 	friend class YTab;
@@ -165,6 +170,8 @@ private:
 			float				InsetForTab(XTab* tab) const;
 			float				InsetForTab(YTab* tab) const;
 
+			void				UpdateConstraints(BLayoutContext* context);
+
 			void				_RemoveSelfFromTab(XTab* tab);
 			void				_RemoveSelfFromTab(YTab* tab);
 			bool				_HasTabInLayout(XTab* tab);
@@ -174,15 +181,7 @@ private:
 
 			BLayoutItem*		_LayoutItemToAdd(BView* view);
 
-			void				_UpdateAreaConstraints();
-
-			BSize				_CalculateMinSize();
-			BSize				_CalculateMaxSize();
-			BSize				_CalculatePreferredSize();
-
-			bool				_TrySolve();
-
-			LinearProgramming::LinearSpec*	fSolver;
+			BPrivate::SharedSolver* fSolver;
 
 			BReference<XTab>	fLeft;
 			BReference<XTab>	fRight;

headers/libs/linprog/LinearSpec.h

@@ -55,6 +55,9 @@ public:
 	virtual	BSize				MinSize(Variable* width, Variable* height) = 0;
 	virtual	BSize				MaxSize(Variable* width, Variable* height) = 0;
 
+	virtual	ResultType			FindMins(const VariableList* variables) = 0;
+	virtual	ResultType			FindMaxs(const VariableList* variables) = 0;
+
 protected:
 			LinearSpec*			fLinearSpec; 
 };
@@ -122,6 +125,9 @@ public:
 			BSize				MinSize(Variable* width, Variable* height);
 			BSize				MaxSize(Variable* width, Variable* height);
 
+			ResultType			FindMins(const VariableList* variables);
+			ResultType			FindMaxs(const VariableList* variables);
+
 			ResultType			Solve();
 			bool				Save(const char* fileName);