CTextBox: ensure paint of text and background only if required

It's not new, but this involves also other properties,
like color or position...

It's possible that more properties are required, maybe needs to be watched
and evaluation of comparison might require further revisions.

src/gui/widget/textbox.cpp

@@ -77,7 +77,7 @@ CTextBox::CTextBox(const char * text, Font* font_text, const int pmode,
 	initVar();
 
 	if(text != NULL)
-		m_cText = text;
+		m_cText = m_old_cText = text;
 	
 	if(font_text != NULL)
 		m_pcFontText = font_text;
@@ -113,7 +113,7 @@ CTextBox::CTextBox(const char * text)
 	initVar();
 
 	if(text != NULL)
-		m_cText = *text;
+		m_cText = m_old_cText = *text;
 
 	//TRACE_1("[CTextBox] %s Line %d text: %s\r\n", __FUNCTION__, __LINE__, text);
 
@@ -149,7 +149,7 @@ void CTextBox::initVar(void)
 	m_nMaxLineWidth = 0;
 
 	m_cText	= "";
-	m_nMode = SCROLL;
+	m_nMode = m_old_nMode 	= SCROLL;
 
 	m_FontUseDigitHeight	= false;
 	m_pcFontText  		= g_Font[SNeutrinoSettings::FONT_TYPE_EPG_INFO1];
@@ -164,21 +164,21 @@ void CTextBox::initVar(void)
 	text_Hborder_width 	= 8; //border left and right
 	text_Vborder_width	= 8; //border top and buttom
 
-	m_cFrame.iX		= g_settings.screen_StartX + ((g_settings.screen_EndX - g_settings.screen_StartX - MIN_WINDOW_WIDTH) >>1);
+	m_cFrame.iX		= m_old_x = g_settings.screen_StartX + ((g_settings.screen_EndX - g_settings.screen_StartX - MIN_WINDOW_WIDTH) >>1);
-	m_cFrame.iWidth		= MIN_WINDOW_WIDTH;
+	m_cFrame.iWidth		= m_old_dx = MIN_WINDOW_WIDTH;
-	m_cFrame.iY		= g_settings.screen_StartY + ((g_settings.screen_EndY - g_settings.screen_StartY - MIN_WINDOW_HEIGHT) >>1);
+	m_cFrame.iY		= m_old_y = g_settings.screen_StartY + ((g_settings.screen_EndY - g_settings.screen_StartY - MIN_WINDOW_HEIGHT) >>1);
-	m_cFrame.iHeight	= MIN_WINDOW_HEIGHT;
+	m_cFrame.iHeight	= m_old_dy = MIN_WINDOW_HEIGHT;
 
 	m_nMaxHeight 		= MAX_WINDOW_HEIGHT;
 	m_nMaxWidth 		= MAX_WINDOW_WIDTH;
 	m_nMinHeight		= MIN_WINDOW_HEIGHT;
 	m_nMinWidth		= MIN_WINDOW_WIDTH;
 
-	m_textBackgroundColor 	= COL_MENUCONTENT_PLUS_0;
+	m_textBackgroundColor 	= m_old_textBackgroundColor = COL_MENUCONTENT_PLUS_0;
 	m_textColor		= COL_MENUCONTENT_TEXT;
 	m_nPaintBackground 	= true;
-	m_nBgRadius		= 0;
+	m_nBgRadius		= m_old_nBgRadius = 0;
-	m_nBgRadiusType 	= CORNER_ALL;
+	m_nBgRadiusType 	= m_old_nBgRadiusType = CORNER_ALL;
 
 	m_cLineArray.clear();
 
@@ -516,25 +516,68 @@ void CTextBox::refreshText(void)
 	int ay = /*m_cFrameTextRel.iY+*/m_cFrame.iY;
 	int dx = m_cFrameTextRel.iWidth;
 	int dy = m_cFrameTextRel.iHeight;
+	bool has_changed = false;
 
-	//save screen
+	//evaluate comparsion properties
+	if (m_old_x != ax || m_old_y != ay || m_old_dx != dx || m_old_dy != dy ||
+		m_old_textBackgroundColor != m_textBackgroundColor ||
+		m_old_nBgRadius != m_nBgRadius ||m_old_nBgRadiusType != m_nBgRadiusType ||
+		m_nNrOfPages > 1 ||
+		m_old_nMode != m_nMode){
+			has_changed = true;
+	}
+
+	//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;
+		}
+	}
+
+	//save screen only if no paint of background required
+	if (!m_nPaintBackground){
 		if (m_bgpixbuf == NULL){
+			//TRACE("[CTextBox] %s save bg %d\r\n", __FUNCTION__, __LINE__);
 			m_bgpixbuf= new fb_pixel_t[dx * dy];
 			frameBuffer->SaveScreen(ax, ay, dx, dy, m_bgpixbuf);
 		}
+	}
 
 	//Paint Text Background
 	if (m_nPaintBackground){
 		if (m_bgpixbuf){
+			//TRACE("[CTextBox] %s destroy bg %d\r\n", __FUNCTION__, __LINE__);
 			delete[] m_bgpixbuf;
 			m_bgpixbuf = NULL;
 		}
+		if (has_changed){
+			//TRACE("[CTextBox] %s paint bg %d\r\n", __FUNCTION__, __LINE__);
 			frameBuffer->paintBoxRel(ax, ay, dx, dy,  m_textBackgroundColor, m_nBgRadius, m_nBgRadiusType);
 		}
+	}
 	else{
-		if (m_bgpixbuf)
+		if (m_bgpixbuf){
+			if (m_old_cText != m_cText || has_changed){
+				//TRACE("[CTextBox] %s restore bg %d\r\n", __FUNCTION__, __LINE__);
 				frameBuffer->RestoreScreen(ax, ay, dx, dy, m_bgpixbuf);
 			}
+		}
+	}
+
+	//save current comparsion properties
+	if (has_changed){
+		//TRACE("[CTextBox] %s set current values %d\r\n", __FUNCTION__, __LINE__);
+		m_old_x = ax;
+		m_old_y = ay;
+		m_old_dx = dx;
+		m_old_dy = dy;
+		m_old_textBackgroundColor = m_textBackgroundColor;
+		m_old_nBgRadius = m_nBgRadius;
+		m_old_nBgRadiusType = m_nBgRadiusType;
+		m_old_nMode = m_nMode;
+	}
 
 	if( m_nNrOfLines <= 0)
 		return;
@@ -571,6 +614,7 @@ void CTextBox::refreshText(void)
 		m_pcFontText->RenderString(m_cFrame.iX + m_cFrameTextRel.iX + text_Hborder_width + x_center,
 					y+m_cFrame.iY, m_cFrameTextRel.iWidth, m_cLineArray[i].c_str(),
 					m_textColor, 0, true); // UTF-8
+		m_old_cText = m_cText;
 		y += m_nFontTextHeight;
 	}
 }

src/gui/widget/textbox.h

@@ -116,9 +116,12 @@ class CTextBox
 		int  getFontTextHeight();
 
 		/* Variables */
-		std::string m_cText;
+		std::string m_cText, m_old_cText;
 		std::vector<std::string> m_cLineArray;
 
+		int m_old_x, m_old_y, m_old_dx, m_old_dy, m_old_nBgRadius, m_old_nBgRadiusType, m_old_nMode;
+		fb_pixel_t m_old_textBackgroundColor;
+
 		bool m_showTextFrame;
 
 		CBox m_cFrame;