CTextBox: add/modify methodes for screen handlings

- split hasChanged() into hasChangedPos(), hasChangedDim()
- add return value bool to enableBackgroundPaint(), enableSaveScreen()
- add clearScreenBuffer(), for unified usage in destructor and functions
- add OnAfterRefresh() as a signal/slot handler, this allows to use
 external methodes as callbacks after painted text


Origin commit data
------------------
Commit: a2171dad4a
Author: Thilo Graf <dbt@novatux.de>
Date: 2015-11-18 (Wed, 18 Nov 2015)

Origin message was:
------------------
CTextBox: add/modify methodes for screen handlings

- split hasChanged() into hasChangedPos(), hasChangedDim()
- add return value bool to enableBackgroundPaint(), enableSaveScreen()
- add clearScreenBuffer(), for unified usage in destructor and functions
- add OnAfterRefresh() as a signal/slot handler, this allows to use
 external methodes as callbacks after painted text

src/gui/widget/textbox.cpp

@@ -135,7 +135,7 @@ CTextBox::~CTextBox()
 	//TRACE("[CTextBox] del\r\n");
 	m_cLineArray.clear();
 	//hide();
-	delete[] m_bgpixbuf;
+	clearScreenBuffer();
 }
 
 void CTextBox::initVar(void)
@@ -515,10 +515,8 @@ void CTextBox::refreshScroll(void)
 //first init is done in initVar() and reinit done in reInitToCompareVar()
 bool CTextBox::hasChanged(int* x, int* y, int* dx, int* dy)
 {
-	if (	   m_old_x != *x
-		|| m_old_y != *y
-		|| m_old_dx != *dx
-		|| m_old_dy != *dy
+	if (	   hasChangedPos(x, y)
+		|| hasChangedDim(dx, dy)
 		|| m_old_textBackgroundColor != m_textBackgroundColor
 		|| m_old_textColor != m_textColor
 		|| m_old_nBgRadius != m_nBgRadius
@@ -528,6 +526,17 @@ bool CTextBox::hasChanged(int* x, int* y, int* dx, int* dy)
 	}
 	return false;
 }
+
+bool CTextBox::hasChangedPos(int* x, int* y)
+{
+	return  (m_old_x != *x || m_old_y != *y);
+}
+
+bool CTextBox::hasChangedDim(int* dx, int* dy)
+{
+	return (m_old_dx != *dx || m_old_dy != *dy);
+}
+
 void CTextBox::reInitToCompareVar(int* x, int* y, int* dx, int* dy)
 {
 	m_old_x = *x;
@@ -560,13 +569,14 @@ void CTextBox::refreshText(void)
 	//find changes
 	bool has_changed = hasChanged(&ax, &ay, &dx, &dy);
 
-	//destroy pixel buffer on changed property values
-	if (has_changed){
-		if (m_bgpixbuf){
-			//TRACE("[CTextBox] %s destroy ol pixel buffer, has changes %d\r\n", __FUNCTION__, __LINE__);
-			delete[] m_bgpixbuf;
-			m_bgpixbuf = NULL;
-		}
+	//clean up possible screen on any changes
+	if (has_changed && m_bgpixbuf){
+		/*TODO/FIXME: in some cases could be required, that we must restore old saved screen. eg. if a text without bg was painted
+		 * and another text should be painted as next on the same position like current text, but new text will be overpaint and is
+		 * not visible. It's currently solvable only with appropriate order of text items
+		*/
+		frameBuffer->RestoreScreen(m_old_x, m_old_y, m_old_dx, m_old_dy, m_bgpixbuf);
+		clearScreenBuffer();
 	}
 
 	//detect corrupt position values
@@ -589,11 +599,7 @@ void CTextBox::refreshText(void)
 	//Paint Text Background
 	bool allow_paint_bg = (m_old_cText != m_cText || has_changed || m_has_scrolled);
 	if (m_nPaintBackground){
-		if (m_bgpixbuf){
-			//TRACE("[CTextBox] %s destroy bg %d\r\n", __FUNCTION__, __LINE__);
-			delete[] m_bgpixbuf;
-			m_bgpixbuf = NULL;
-		}
+		clearScreenBuffer();
 		if (allow_paint_bg){
 			//TRACE("[CTextBox] %s paint bg %d\r\n", __FUNCTION__, __LINE__);
 			frameBuffer->paintBoxRel(ax, ay, dx, dy,  m_textBackgroundColor, m_nBgRadius, m_nBgRadiusType);
@@ -713,6 +719,7 @@ void CTextBox::refresh(void)
 	//Paint text
 	refreshScroll();
 	refreshText();
+	OnAfterRefresh();
 }
 
 
@@ -772,3 +779,28 @@ void CTextBox::hide (void)
 
 	frameBuffer = NULL;
 }
+
+bool CTextBox::clearScreenBuffer()
+{
+	if(m_bgpixbuf){
+		//TRACE("[CTextBox] %s destroy bg %d\r\n", __FUNCTION__, __LINE__);
+		delete[] m_bgpixbuf;
+		m_bgpixbuf = NULL;
+		return true;
+	}
+	return false;
+}
+
+bool CTextBox::enableSaveScreen(bool mode)
+{
+	if (m_SaveScreen == mode)
+		return false;
+
+	if (!m_SaveScreen || m_SaveScreen != mode)
+		clearScreenBuffer();
+
+	m_SaveScreen = mode;
+
+	return true;
+}
+

src/gui/widget/textbox.h

@@ -62,7 +62,7 @@
 #include <driver/fb_window.h>
 #include <gui/color.h>
 #include <gui/customcolor.h>
-
+#include <sigc++/signal.h>
 #define TRACE  printf
 #define TRACE_1 printf
 
@@ -81,7 +81,7 @@ class CBox
 		int iHeight;
 };
 
-class CTextBox
+class CTextBox : public sigc::trackable
 {
 	public:
 		/* Variables */
@@ -110,6 +110,8 @@ class CTextBox
 		void reSizeMainFrameHeight(int maxTextHeight);
 		
 		bool hasChanged(int* x, int* y, int* dx, int* dy);
+		bool hasChangedPos(int* x, int* y);
+		bool hasChangedDim(int* dx, int* dy);
 		void reInitToCompareVar(int* x, int* y, int* dx, int* dy);
 
 		/* Variables */
@@ -179,8 +181,9 @@ class CTextBox
 		void    refresh(void);
 		void    scrollPageDown(const int pages);
 		void    scrollPageUp(const int pages);
-		void    enableBackgroundPaint(bool mode = true){m_nPaintBackground = mode;};
-		void    enableSaveScreen(bool mode = true){m_SaveScreen = mode;};
+		void    enableBackgroundPaint(bool mode = true){m_nPaintBackground = mode;}
+		//enable screen saving behind chars, is required for transparent text paint, returns true if mode was changed
+		bool    enableSaveScreen(bool mode = true);
 		bool	setText(const std::string* newText, int max_width = 0, bool force_repaint = true);
 		void 	setTextColor(fb_pixel_t color_text){ m_textColor = color_text;};
 		void	setBackGroundRadius(const int radius, const int type = CORNER_ALL){m_nBgRadius = radius; m_nBgRadiusType = type;};
@@ -207,6 +210,8 @@ class CTextBox
 		inline int	getTextMode()			{return m_nMode;};
 		void paint (void);
 		void hide (void);
+		bool clearScreenBuffer();
+		sigc::signal<void> OnAfterRefresh;
 };
 
 #endif // !defined(AFX_TEXTBOX_H__208DED01_ABEC_491C_A632_5B21057DC5D8__INCLUDED_)