Scintilla GTK patch to add drop shadow below text

sci-shadow.patch

diff --git a/scintilla/gtk/PlatGTK.cxx b/scintilla/gtk/PlatGTK.cxx
index 90f5c07..2206847 100644
--- a/scintilla/gtk/PlatGTK.cxx
+++ b/scintilla/gtk/PlatGTK.cxx
@@ -45,6 +45,8 @@
 
 #define USE_CAIRO 1
 
+static double shadow_colour;
+
 #ifdef USE_CAIRO
 
 static cairo_surface_t *CreateSimilarSurface(GdkWindow *window, cairo_content_t content, int width, int height) {
@@ -764,6 +766,8 @@ class SurfaceImpl : public Surface {
 	Converter conv;
 	int characterSet;
 	void SetConverter(int characterSet_);
+	void PenShadowColour();
+	void SetShadowColorFromBack(ColourAllocated back, double shade);
 public:
 	SurfaceImpl();
 	virtual ~SurfaceImpl();
@@ -1045,6 +1049,41 @@ void SurfaceImpl::PenColour(ColourAllocated fore) {
 #endif
 }
 
+// Call this whenever there's a new bg color before drawing text
+void SurfaceImpl::SetShadowColorFromBack(ColourAllocated back, double shade=0.1) {
+	// Skip (re)setting when default/black colour is used (FIXME)
+	if (back.AsLong() != 0) {
+		ColourDesired desired_colour(back.AsLong());
+
+		// Perform very simple conversion from RGB to grayscale
+		shadow_colour = (
+			desired_colour.GetRed() / 256.0 +
+			desired_colour.GetGreen() / 256.0 +
+			desired_colour.GetBlue() / 256.0) / 3.0;
+
+		// Lighten or darken depending on the background colour
+		//if (shadow_colour >= 0.5)
+			shadow_colour = shadow_colour - shade;
+		//else
+		//	shadow_colour = shadow_colour + shade;
+
+		// Clamp between 0.0 and 1.0
+		if (shadow_colour < 0.0) shadow_colour = 0.0;
+		if (shadow_colour > 1.0) shadow_colour = 1.0;
+	}
+}
+
+void SurfaceImpl::PenShadowColour() {
+#ifdef USE_CAIRO
+	if (context) {
+		cairo_set_source_rgb(context,
+			shadow_colour,
+			shadow_colour,
+			shadow_colour);
+	}
+#endif
+}
+
 int SurfaceImpl::LogPixelsY() {
 	return 72;
 }
@@ -1618,6 +1657,10 @@ void SurfaceImpl::DrawTextBase(PRectangle rc, Font &font_, int ybase, const char
 			PangoLayoutLine *pll = pango_layout_get_line(layout,0);
 #endif
 #ifdef USE_CAIRO
+			PenShadowColour();
+			cairo_move_to(context, xText+1, ybase+1);
+			pango_cairo_show_layout_line(context, pll);
+			PenColour(fore);
 			cairo_move_to(context, xText, ybase);
 			pango_cairo_show_layout_line(context, pll);
 #else
@@ -1681,6 +1724,7 @@ void SurfaceImpl::DrawTextBase(PRectangle rc, Font &font_, int ybase, const char
 void SurfaceImpl::DrawTextNoClip(PRectangle rc, Font &font_, int ybase, const char *s, int len,
                                  ColourAllocated fore, ColourAllocated back) {
 	FillRectangle(rc, back);
+	SetShadowColorFromBack(back);
 	DrawTextBase(rc, font_, ybase, s, len, fore);
 }
 
@@ -1688,11 +1732,14 @@ void SurfaceImpl::DrawTextNoClip(PRectangle rc, Font &font_, int ybase, const ch
 void SurfaceImpl::DrawTextClipped(PRectangle rc, Font &font_, int ybase, const char *s, int len,
                                   ColourAllocated fore, ColourAllocated back) {
 	FillRectangle(rc, back);
+	SetShadowColorFromBack(back);
 	DrawTextBase(rc, font_, ybase, s, len, fore);
 }
 
 void SurfaceImpl::DrawTextTransparent(PRectangle rc, Font &font_, int ybase, const char *s, int len,
                                   ColourAllocated fore) {
+	// Missing back parameter
+	// SetShadowColorFromBack(back);
 	// Avoid drawing spaces in transparent mode
 	for (int i=0;i<len;i++) {
 		if (s[i] != ' ') {

Hmm, seems to work here with a variety of font sizes and colours at my LCD's native resolution. It does look better though if the shadow is just always made darker even on dark backgrounds, like in the latest version of this Gist.

About the code, yeah, I pointed out in IRC it was garbage. Moving shadow_colour to the global scope from the class's scope is what finally made it actually work, since many Surfaces are created but not always getting the background colour set, this stores the background colour across Surfaces when it is set, which conveniently works fine in Geany since all Scintilla widgets always have the same background colour.

It's nothing I'd send upstream or even try to get into Geany, but alas I now have my drop shadowed text :)

On 8 February 2012 02:11, Matthew Brush ***@***.*** wrote: Hmm, seems to work here with a variety of font sizes and colours at my LCD's native resolution. It does look better though if the shadow is just always made darker even on dark backgrounds, like in the latest version of this Gist. About the code, yeah, I pointed out in IRC it was garbage. Moving shadow_colour to the global scope from the class's scope is what finally made it actually work, since many Surfaces are created but not always getting the background colour set, this stores the background colour across Surfaces when it is set, which conveniently works fine in Geany since all Scintilla widgets always have the same background colour. It's nothing I'd send upstream or even try to get into Geany, but alas I now have my drop shadowed text :)

As I have said elsewhere, its nice that you can make a Geany that is broke the way you like it :)

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