BTab: decouple display label from view name.

In BeOS, the tab label was synchronized with the view name. This means
BTab::SetLabel would change the view name. This behavior is unexpected,
and also annoying, for example it prevents using localized tab labels
but fixed view names for scripting.

* Document this divergence from BeOS in the Haiku book
* Detect if we're running in a BeOS app to preserve the old behavior
  then

Change-Id: I5b758a035fe8752cee2ea7789a30ea47a01467b9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/122
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Jérôme Duval <[email protected]>

docs/user/interface/TabView.dox

@@ -140,6 +140,8 @@
 /*!
 	\fn const char* BTab::Label() const
 	\brief Returns the tab's label (the target view's name).
+	\warning In BeOS, the tab label is determined from the view name. In Haiku, they can be
+		different if SetLabel() was used.
 
 	\since BeOS R3
 */
@@ -147,7 +149,9 @@
 
 /*!
 	\fn void BTab::SetLabel(const char* label)
-	\brief Sets the target view's name, and updates the BTab accordingly.
+	\brief Sets the tab label.
+	\warning In BeOS, setting the tab label also renamed the view attached to the tab. In Haiku,
+		this is not the case anymore, the label and view name are independant.
 
 	\since BeOS R3
 */
@@ -220,6 +224,9 @@
 /*!
 	\fn void BTab::SetView(BView* view)
 	\brief Sets the view to be displayed for this tab.
+
+	This also resets the tab label to match the view name (to preserve BeOS behavior).
+	If you need to use a different label, SetLabel must be called after SetView.
 */
 
 

headers/os/interface/TabView.h

@@ -82,8 +82,13 @@ private:
 			bool				fFocus;
 			BView*				fView;
 			BTabView*			fTabView;
+			BString				fLabel;
 
-			uint32				_reserved[11];
+#ifdef B_HAIKU_64_BIT
+			uint32				_reserved[9];
+#else
+			uint32				_reserved[10];
+#endif
 };
 
 

src/kits/interface/TabView.cpp

@@ -32,6 +32,7 @@
 #include <Window.h>
 
 #include <binary_compatibility/Support.h>
+#include <private/libroot/libroot_private.h>
 
 
 static property_info sPropertyList[] = {
@@ -47,14 +48,26 @@ static property_info sPropertyList[] = {
 };
 
 
+static bool
+IsLayouted(BView* childView)
+{
+	BView* container = childView->Parent();
+	if (container != NULL)
+		return dynamic_cast<BCardLayout*>(container->GetLayout()) != NULL;
+	return false;
+}
+
+
 BTab::BTab(BView* contentsView)
 	:
 	fEnabled(true),
 	fSelected(false),
 	fFocus(false),
-	fView(contentsView),
-	fTabView(NULL)
+	fView(contentsView)
 {
+	fTabView = NULL;
+	if (fView != NULL)
+		fLabel = fView->Name();
 }
 
 
@@ -63,9 +76,10 @@ BTab::BTab(BMessage* archive)
 	BArchivable(archive),
 	fSelected(false),
 	fFocus(false),
-	fView(NULL),
-	fTabView(NULL)
+	fView(NULL)
 {
+	fTabView = NULL;
+
 	bool disable;
 
 	if (archive->FindBool("_disable", &disable) != B_OK)
@@ -121,10 +135,17 @@ BTab::Perform(uint32 d, void* arg)
 const char*
 BTab::Label() const
 {
+#ifdef __HAIKU_BEOS_COMPATIBLE
+	if (__gABIVersion >= B_HAIKU_ABI_GCC_2_HAIKU)
+		return fLabel;
+
 	if (fView != NULL)
 		return fView->Name();
-	else
-		return NULL;
+
+	return NULL;
+#else
+	return fLabel;
+#endif
 }
 
 
@@ -134,7 +155,11 @@ BTab::SetLabel(const char* label)
 	if (label == NULL || fView == NULL)
 		return;
 
-	fView->SetName(label);
+#ifdef __HAIKU_BEOS_COMPATIBLE
+	if (__gABIVersion < B_HAIKU_ABI_GCC_2_HAIKU)
+		fView->SetName(label);
+#endif
+	fLabel = label;
 
 	if (fTabView != NULL)
 		fTabView->Invalidate();
@@ -169,12 +194,7 @@ BTab::Deselect()
 	if (fView != NULL) {
 		// NOTE: Views are not added/removed, if there is layout,
 		// they are made visible/invisible in that case.
-		bool removeView = false;
-		BView* container = fView->Parent();
-		if (container != NULL)
-			removeView =
-				dynamic_cast<BCardLayout*>(container->GetLayout()) == NULL;
-		if (removeView)
+		if (!IsLayouted(fView))
 			fView->RemoveSelf();
 	}
 
@@ -221,6 +241,7 @@ BTab::SetView(BView* view)
 		delete fView;
 	}
 	fView = view;
+	fLabel = fView->Name();
 
 	if (fTabView != NULL && fSelected) {
 		Select(fTabView->ContainerView());