* Added LinkReceiver methods that return the length of the string.

* AS_GET_STRING_WIDTHS now uses this method to send the strings to the app_server;
  ie. it no longer sends the whole strings, and it saves sending the string length
  separately.
* BFont::StringWidth() will now always return 0.0f in case of an error (instead of
  some random value)
* Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16525 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/app/LinkReceiver.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2005, Haiku.
+ * Copyright 2001-2006, Haiku.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -32,13 +32,12 @@ class LinkReceiver {
 		int32 Code() const;
 
 		virtual status_t Read(void *data, ssize_t size);
-		status_t ReadString(char **string);
-		status_t ReadString(BString& string);
+		status_t ReadString(char** _string, size_t* _length = NULL);
+		status_t ReadString(BString& string, size_t* _length = NULL);
 		status_t ReadString(char *buffer, size_t bufferSize);
+
 		template <class Type> status_t Read(Type *data)
-		{
-			return Read(data, sizeof(Type));
-		}
+			{ return Read(data, sizeof(Type)); }
 
 	protected:
 		virtual status_t ReadFromPort(bigtime_t timeout);

headers/private/app/ServerLink.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2005, Haiku.
+ * Copyright 2001-2006, Haiku.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -60,8 +60,8 @@ class ServerLink {
 		bool NeedsReply() const;
 		status_t Read(void *data, ssize_t size);
 		status_t ReadString(char *buffer, size_t bufferSize);
-		status_t ReadString(BString& string);
-		status_t ReadString(char **string);
+		status_t ReadString(BString& string, size_t* _length = NULL);
+		status_t ReadString(char** _string, size_t* _length = NULL);
 		status_t ReadRegion(BRegion *region);
 		status_t ReadShape(BShape *shape);
 		template <class Type> status_t Read(Type *data);
@@ -173,15 +173,15 @@ ServerLink::ReadString(char *buffer, size_t bufferSize)
 }
 
 inline status_t
-ServerLink::ReadString(BString& string)
+ServerLink::ReadString(BString& string, size_t* _length)
 {
-	return fReceiver->ReadString(string);
+	return fReceiver->ReadString(string, _length);
 }
 
 inline status_t
-ServerLink::ReadString(char **string)
+ServerLink::ReadString(char** _string, size_t* _length)
 {
-	return fReceiver->ReadString(string);
+	return fReceiver->ReadString(_string, _length);
 }
 
 template <class Type> status_t

src/kits/interface/Font.cpp

@@ -984,9 +984,9 @@ float
 BFont::StringWidth(const char *string, int32 length) const
 {
 	if (!string || length < 1)
-		return 0.0;
+		return 0.0f;
 
-	float width;
+	float width = 0.0f;
 	GetStringWidths(&string, &length, 1, &width);
 
 	return width;
@@ -1011,13 +1011,12 @@ BFont::GetStringWidths(const char *stringArray[], const int32 lengthArray[],
 	// TODO: all strings into a single array???
 	//	we do have a maximum message length, and it could be easily touched here...
 	for (int32 i = 0; i < numStrings; i++) {
-		link.Attach<int32>(lengthArray[i]);
-		link.AttachString(stringArray[i]);
+		link.AttachString(stringArray[i], lengthArray[i]);
 	}
 
-	int32 code;
-	if (link.FlushWithReply(code) != B_OK
-		|| code != B_OK)
+	status_t status;
+	if (link.FlushWithReply(status) != B_OK
+		|| status != B_OK)
 		return;
 
 	link.Read(widthArray, sizeof(float) * numStrings);
@@ -1046,8 +1045,8 @@ BFont::GetEscapements(const char charArray[], int32 numChars, escapement_delta *
 	link.Attach<float>(fRotation);
 	link.Attach<uint32>(fFlags);
 
-	link.Attach<float>(delta ? delta->nonspace : 0.0);
-	link.Attach<float>(delta ? delta->space : 0.0);
+	link.Attach<float>(delta ? delta->nonspace : 0.0f);
+	link.Attach<float>(delta ? delta->space : 0.0f);
 	link.Attach<int32>(numChars);
 
 	// TODO: Should we not worry about the port capacity here?!?

src/servers/app/ServerApp.cpp

@@ -1401,23 +1401,22 @@ ServerApp::_DispatchMessage(int32 code, BPrivate::LinkReceiver& link)
 			link.Read<float>(&size);
 			link.Read<uint8>(&spacing);
 			int32 numStrings;
-			link.Read<int32>(&numStrings);
+			if (link.Read<int32>(&numStrings) != B_OK) {
+				// this results in a B_BAD_VALUE return
+				numStrings = 0;
+				size = 0.0f;
+			}
 
 			float widthArray[numStrings];
 			int32 lengthArray[numStrings];
 			char *stringArray[numStrings];
 			for (int32 i = 0; i < numStrings; i++) {
-				// TODO: the length is actually encoded twice here
-				//	It would be nicer to only send as much from the string as needed
-				link.Read<int32>(&lengthArray[i]);
-				link.ReadString(&stringArray[i]);
+				link.ReadString(&stringArray[i], (size_t *)&lengthArray[i]);
 			}
 
 			ServerFont font;
 
-			if (font.SetFamilyAndStyle(family, style) == B_OK
-				&& size > 0) {
-
+			if (font.SetFamilyAndStyle(family, style) == B_OK && size > 0) {
 				font.SetSize(size);
 				font.SetSpacing(spacing);