[Mono-bugs] [Bug 73606][Maj] New - OnCreateControl() called when ClientSize changed, and called more than once

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Changed by 4lw0e0402@sneakemail.com.

http://bugzilla.ximian.com/show_bug.cgi?id=73606

--- shadow/73606	2005-03-11 13:50:34.000000000 -0500
+++ shadow/73606.tmp.1749	2005-03-11 13:50:35.000000000 -0500
@@ -0,0 +1,106 @@
+Bug#: 73606
+Product: Mono: Class Libraries
+Version: unspecified
+OS: other
+OS Details: platforms using the XplatUIX11 driver
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Major
+Component: Windows.Forms
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: 4lw0e0402@sneakemail.com               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: OnCreateControl() called when ClientSize changed, and called more than once
+
+Description of Problem:
+  With Microsoft's S.W.F implementation, adjusting a control's ClientSize
+  before it has been realized does not realize the control. With the
+  current mono implementation, Control::SetClientSizeCore () always reads
+  the Control::Handle property, which realizes the control and calls
+  CreateControl ().
+
+  In addition, with Microsoft's implementation, OnCreateControl () is only
+  ever called once, regardless of how many times CreateControl () is
+  called. With mono's implementation, OnCreateControl () is called twice
+  the first time CreateControl () is called and once more for each
+  additional call.
+
+Steps to reproduce the problem:
+1. Create a subclass of Control with some debug output code in an override 
+of the OnCreateControl () method.
+2. In that Control's constructor, adjust ClientSize between two other 
+debug output calls.
+3. Insert several calls to CreateControl () in the control.
+4. Create an instance of the control.
+
+class TestControl : System.Windows.Forms.Control
+{
+  public TestControl (bool call_create_control)
+  {
+    if (call_create_control)
+      CreateControl();
+
+    System.Console.WriteLine ("  Before assignment to ClientSize");
+    ClientSize = new System.Drawing.Size(500, 300);
+    System.Console.WriteLine ("  After assignment to ClientSize");
+  }
+
+  protected override void OnCreateControl ()
+  {
+    System.Console.WriteLine ("  OnCreateControl () called");
+  }
+
+  static void Main ()
+  {
+    System.Console.WriteLine ("First object:");
+    new TestControl (false).CreateControl ();
+    System.Console.WriteLine ("Second object:");
+    new TestControl (true).CreateControl ();
+  }
+}
+
+Actual Results:
+  With the above test code, the Microsoft runtime's output is:
+
+First object:
+  Before assignment to ClientSize
+  After assignment to ClientSize
+  OnCreateControl () called
+Second object:
+  OnCreateControl () called
+  Before assignment to ClientSize
+  After assignment to ClientSize
+
+With mono svn, the output is:
+
+First object:
+Mono System.Windows.Forms Assembly [Revision: 41586; built: 2005/2/9 
+1:7:30]
+Keyboard: United States keyboard layout (phantom key version)
+  Before assignment to ClientSize
+  OnCreateControl () called
+  After assignment to ClientSize
+  OnCreateControl () called
+Second object:
+  OnCreateControl () called
+  OnCreateControl () called
+  Before assignment to ClientSize
+  After assignment to ClientSize
+  OnCreateControl () called
+
+Expected Results:
+  Mono should follow the Microsoft runtime's behaviour.
+
+Additional Information:
+  The attached Control.cs implements an alternate solution to bug #73190.
+  With it installed, the mono runtime's output is identical to Microsoft's.
+  It takes a different approach: Instead of trying to avoid spurious
+  calls to Control::CreateControl (), it ensures that it only calls
+  Control::OnCreateControl () once from Control::CreateControl (). The
+  existing SVN fix to bug #73190 has Control::CreateHandle () call
+  Control::CreateControl (); the attached Control.cs reverses this,
+  replacing a number of calls to CreateHandle () to CreateControl ().