ScreenSaver: Add "No preview available" text

... when a screensaver doesn't provide a preview.

Also do a bit of refactoring in PreviewView, remove unneeded includes

src/preferences/screensaver/Jamfile

@@ -30,5 +30,6 @@ DoCatalogs ScreenSaver :
 	x-vnd.Haiku-ScreenSaver
 	:
 	PasswordWindow.cpp
+	PreviewView.cpp
 	ScreenSaverWindow.cpp
 	;

src/preferences/screensaver/PreviewView.cpp

@@ -9,17 +9,21 @@
 
 
 #include "PreviewView.h"
-#include "Utility.h"
-
-#include <Point.h>
-#include <Rect.h>
-#include <Screen.h>
-#include <ScreenSaver.h>
-#include <Shape.h>
-#include <String.h>
 
 #include <iostream>
 
+#include <Catalog.h>
+#include <Point.h>
+#include <Rect.h>
+#include <Size.h>
+#include <TextView.h>
+
+#include "Utility.h"
+
+
+#undef B_TRANSLATION_CONTEXT
+#define B_TRANSLATION_CONTEXT "PreviewView"
+
 
 static float sampleX[]
 	= { 0, 0.05, 0.15, 0.7, 0.725, 0.8, 0.825, 0.85, 0.950, 1.0 };
@@ -41,10 +45,14 @@ scale2(int x1, int x2, int y1, int y2, BRect area)
 }
 
 
+//	#pragma mark - PreviewView
+
+
 PreviewView::PreviewView(const char* name)
 	:
 	BView(name, B_WILL_DRAW),
-	fSaverView(NULL)
+	fSaverView(NULL),
+	fNoPreview(NULL)
 {
 	SetViewColor(ui_color(B_PANEL_BACKGROUND_COLOR));
 
@@ -96,13 +104,30 @@ PreviewView::Draw(BRect updateRect)
 BView*
 PreviewView::AddPreview()
 {
-	BRect rect = scale2(1, 8, 1, 2, Bounds());
-	fSaverView = new BView(rect.InsetBySelf(1, 1), "preview", B_FOLLOW_NONE,
-		B_WILL_DRAW);
+	BRect rect(scale2(1, 8, 1, 2, Bounds()).InsetBySelf(1.0f, 1.0f));
+	fSaverView = new BView(rect, "preview", B_FOLLOW_NONE, B_WILL_DRAW);
 	fSaverView->SetViewColor(0, 0, 0);
 	fSaverView->SetLowColor(0, 0, 0);
 	AddChild(fSaverView);
 
+	BRect textRect(rect);
+	textRect.OffsetTo(-7.0f, 0.0f);
+	textRect.InsetBy(15.0f, 20.0f);
+	fNoPreview = new BTextView(rect, "no preview", textRect, B_FOLLOW_NONE,
+		B_WILL_DRAW);
+	fNoPreview->SetViewColor(0, 0, 0);
+	fNoPreview->SetLowColor(0, 0, 0);
+	fNoPreview->SetFontAndColor(be_plain_font, B_FONT_ALL,
+		&(rgb_color){ 255, 255, 255 });
+	fNoPreview->SetText(B_TRANSLATE("No preview available"));
+	fNoPreview->SetAlignment(B_ALIGN_CENTER);
+	fNoPreview->MakeEditable(false);
+	fNoPreview->MakeResizable(false);
+	fNoPreview->MakeSelectable(false);
+
+	fNoPreview->Hide();
+	fSaverView->AddChild(fNoPreview);
+
 	return fSaverView;
 }
 
@@ -124,3 +149,17 @@ PreviewView::SaverView()
 {
 	return fSaverView;
 }
+
+
+void
+PreviewView::ShowNoPreview() const
+{
+	fNoPreview->Show();
+}
+
+
+void
+PreviewView::HideNoPreview() const
+{
+	fNoPreview->Hide();
+}

src/preferences/screensaver/PreviewView.h

@@ -10,11 +10,11 @@
 #define PREVIEW_VIEW_H
 
 
-#include <Box.h>
-#include <ScreenSaverRunner.h>
 #include <View.h>
 
 
+class BTextView;
+
 class PreviewView : public BView {
 public:
 								PreviewView(const char* name);
@@ -26,8 +26,12 @@ public:
 			BView*				RemovePreview();
 			BView*				SaverView();
 
+			void				ShowNoPreview() const;
+			void				HideNoPreview() const;
+
 private:
 			BView*				fSaverView;
+			BTextView*			fNoPreview;
 };
 
 

src/preferences/screensaver/ScreenSaverWindow.cpp

@@ -36,6 +36,7 @@
 #include <Roster.h>
 #include <Screen.h>
 #include <ScreenSaver.h>
+#include <ScreenSaverRunner.h>
 #include <ScrollView.h>
 #include <Size.h>
 #include <Slider.h>
@@ -818,6 +819,8 @@ ModulesView::_OpenSaver()
 		saver->StartConfig(fSettingsView);
 		if (saver->StartSaver(view, true) == B_OK)
 			fSaverRunner->Run();
+		else
+			fPreviewView->ShowNoPreview();
 	}
 
 	if (fSettingsView->ChildAt(0) == NULL) {