sdgui: bind ^W as in Readline

Reusing colours from sdtui configuration would be awkward
and complicated, e.g. with font attributes, so abandon that idea.

CMakeLists.txt

@@ -79,7 +79,7 @@ if (WITH_X11)
 endif ()
 
 pkg_check_modules (gtk gtk+-3.0)
-option (WITH_GUI "Build a work-in-progress GTK+ UI" ${gtk_FOUND})
+option (WITH_GUI "Build an alternative GTK+ UI" ${gtk_FOUND})
 
 link_directories (${dependencies_LIBRARY_DIRS})
 include_directories (${ZLIB_INCLUDE_DIRS} ${icu_INCLUDE_DIRS}

README.adoc

@@ -81,8 +81,9 @@ and general undesirability of terminal UIs, it might be better to start anew.
 
 Graphical UI
 ------------
-With GTK+ 3 development packages installed, an alternative, work-in-progress
-frontend will be built and installed.
+With GTK+ 3 development packages installed, an alternative frontend will be
+built and installed.  It shares the default dictionary list with 'sdtui',
+but styling will follow your theme, and has to be customized from 'gtk.css'.
 
 Contributing and Support
 ------------------------

src/sdgui.c

@@ -246,8 +246,30 @@ main (int argc, char *argv[])
 	if (!load_dictionaries (g.dictionaries, &error))
 		die_with_dialog (error->message);
 
-	// Some Adwaita stupidity
-	const char *style = "notebook header tab { padding: 2px 8px; margin: 0; }";
+	// Some Adwaita stupidity, plus defaults for our own widget.
+	// All the named colours have been there since GNOME 3.4
+	// (see gnome-extra-themes git history, Adwaita used to live there).
+	const char *style = "notebook header tab { padding: 2px 8px; margin: 0; }"
+		// `gsettings set org.gnome.desktop.interface gtk-key-theme "Emacs"`
+		// isn't quite what I want, and note that ^U works by default
+		"@binding-set Readline {"
+			"bind '<Control>H' { 'delete-from-cursor' (chars, -1) };"
+			"bind '<Control>W' { 'delete-from-cursor' (word-ends, -1) }; }"
+		"entry { -gtk-key-bindings: Readline }"
+		"stardict-view { padding: 0 .25em; }"
+		"stardict-view.odd {"
+			"background: @theme_base_color; "
+			"color: @theme_text_color; }"
+		"stardict-view.odd:backdrop {"
+			"background: @theme_unfocused_base_color; "
+			"color: @theme_fg_color; /* should be more faded than 'text' */ }"
+		"stardict-view.even {"
+			"background: mix(@theme_base_color, @theme_text_color, 0.02); "
+			"color: @theme_text_color; }"
+		"stardict-view.even:backdrop {"
+			"background: mix(@theme_unfocused_base_color, "
+				"@theme_fg_color, 0.02); "
+			"color: @theme_fg_color; /* should be more faded than 'text' */ }";
 
 	GdkScreen *screen = gdk_screen_get_default ();
 	GtkCssProvider *provider = gtk_css_provider_new ();
@@ -283,9 +305,6 @@ main (int argc, char *argv[])
 
 	// FIXME: when the clear icon shows, the widget changes in height
 	g.entry = gtk_search_entry_new ();
-	// TODO: attach to the "key-press-event" signal and implement ^W at least,
-	// though ^U is working already!  Note that bindings can be done in CSS
-	// as well, if we have any extra specially for the editor
 	g_signal_connect (g.entry, "changed", G_CALLBACK (on_changed), g.view);
 	// TODO: make the entry have a background colour, rather than transparency
 	gtk_entry_set_has_frame (GTK_ENTRY (g.entry), FALSE);

src/stardict-view.c

@@ -136,24 +136,36 @@ view_entry_height (ViewEntry *ve, gint *word_offset, gint *defn_offset)
 	return MAX (word_y + word_h, defn_y + defn_h);
 }
 
-#define PADDING 5
+static GtkBorder
+view_entry_get_padding (GtkStyleContext *style)
+{
+	GtkBorder padding = {};
+	GtkStateFlags state = gtk_style_context_get_state (style);
+	gtk_style_context_get_padding (style, state, &padding);
+	return padding;
+}
 
 static gint
-view_entry_draw (ViewEntry *ve, cairo_t *cr, gint full_width, gboolean even)
+view_entry_draw (ViewEntry *ve, cairo_t *cr, gint full_width,
+	GtkStyleContext *style)
 {
-	// TODO: this shouldn't be hardcoded, read it out from somewhere
-	gdouble g = even ? 1. : .95;
-
 	gint word_y = 0, defn_y = 0,
 		height = view_entry_height (ve, &word_y, &defn_y);
-	cairo_rectangle (cr, 0, 0, full_width, height);
-	cairo_set_source_rgb (cr, g, g, g);
-	cairo_fill (cr);
 
-	cairo_set_source_rgb (cr, 0, 0, 0);
-	cairo_move_to (cr, full_width / 2 + PADDING, defn_y);
-	pango_cairo_show_layout (cr, ve->definition_layout);
+	gtk_render_background (style, cr, 0, 0, full_width, height);
+	gtk_render_frame (style, cr, 0, 0, full_width, height);
 
+	// Top/bottom and left/right-dependent padding will not work, too much code
+	GtkBorder padding = view_entry_get_padding (style);
+
+	gtk_style_context_save (style);
+	gtk_style_context_add_class (style, GTK_STYLE_CLASS_RIGHT);
+	gtk_render_layout (style, cr,
+		full_width / 2 + padding.left, defn_y, ve->definition_layout);
+	gtk_style_context_restore (style);
+
+	gtk_style_context_save (style);
+	gtk_style_context_add_class (style, GTK_STYLE_CLASS_LEFT);
 	PangoLayoutIter *iter = pango_layout_get_iter (ve->definition_layout);
 	do
 	{
@@ -162,36 +174,43 @@ view_entry_draw (ViewEntry *ve, cairo_t *cr, gint full_width, gboolean even)
 
 		PangoRectangle logical = {};
 		pango_layout_iter_get_line_extents (iter, NULL, &logical);
-		cairo_move_to (cr, PADDING, word_y + PANGO_PIXELS (logical.y));
-		pango_cairo_show_layout (cr, ve->word_layout);
+		gtk_render_layout (style, cr,
+			padding.left, word_y + PANGO_PIXELS (logical.y), ve->word_layout);
 	}
 	while (pango_layout_iter_next_line (iter));
 	pango_layout_iter_free (iter);
+	gtk_style_context_restore (style);
 	return height;
 }
 
 static void
-view_entry_rebuild_layout (ViewEntry *ve, PangoContext *pc, gint width)
+view_entry_rebuild_layouts (ViewEntry *ve, GtkWidget *widget)
 {
+	PangoContext *pc = gtk_widget_get_pango_context (widget);
+	GtkStyleContext *style = gtk_widget_get_style_context (widget);
+	gint full_width = gtk_widget_get_allocated_width (widget);
+
 	g_clear_object (&ve->word_layout);
 	g_clear_object (&ve->definition_layout);
 
-	int left_width = width / 2 - 2 * PADDING;
-	int right_width = width - left_width - 2 * PADDING;
-	if (left_width < 1 || right_width < 1)
+	GtkBorder padding = view_entry_get_padding (style);
+	gint part_width = full_width / 2 - padding.left - padding.right;
+	if (part_width < 1)
 		return;
 
+	// Left/right-dependent fonts aren't supported (GTK_STYLE_PROPERTY_FONT)
 	// TODO: preferably pre-validate the layouts with pango_parse_markup(),
 	//   so that it doesn't warn without indication on the frontend
 	ve->word_layout = pango_layout_new (pc);
 	pango_layout_set_markup (ve->word_layout, ve->word, -1);
 	pango_layout_set_ellipsize (ve->word_layout, PANGO_ELLIPSIZE_END);
 	pango_layout_set_single_paragraph_mode (ve->word_layout, TRUE);
-	pango_layout_set_width (ve->word_layout, PANGO_SCALE * left_width);
+	pango_layout_set_width (ve->word_layout, PANGO_SCALE * part_width);
 
 	ve->definition_layout = pango_layout_new (pc);
 	pango_layout_set_markup (ve->definition_layout, ve->definition, -1);
-	pango_layout_set_width (ve->definition_layout, PANGO_SCALE * right_width);
+	pango_layout_set_width (ve->definition_layout, PANGO_SCALE * part_width);
+	pango_layout_set_wrap (ve->definition_layout, PANGO_WRAP_WORD_CHAR);
 }
 
 // --- Widget ------------------------------------------------------------------
@@ -214,12 +233,9 @@ struct _StardictView
 static ViewEntry *
 make_entry (StardictView *self, StardictIterator *iterator)
 {
-	ViewEntry *ve =
-		view_entry_new (iterator, self->matched ? self->matched : "");
-
-	GtkWidget *widget = GTK_WIDGET (self);
-	view_entry_rebuild_layout (ve, gtk_widget_get_pango_context (widget),
-		gtk_widget_get_allocated_width (widget));
+	const gchar *matched = self->matched ? self->matched : "";
+	ViewEntry *ve = view_entry_new (iterator, matched);
+	view_entry_rebuild_layouts (ve, GTK_WIDGET (self));
 	return ve;
 }
 
@@ -354,10 +370,12 @@ stardict_view_get_preferred_height (GtkWidget *widget,
 }
 
 static void
-stardict_view_get_preferred_width (GtkWidget *widget G_GNUC_UNUSED,
+stardict_view_get_preferred_width (GtkWidget *widget,
 	gint *minimum, gint *natural)
 {
-	*natural = *minimum = 4 * PADDING;
+	GtkStyleContext *style = gtk_widget_get_style_context (widget);
+	GtkBorder padding = view_entry_get_padding (style);
+	*natural = *minimum = 2 * (padding.left + 1 * padding.right);
 }
 
 static void
@@ -387,9 +405,7 @@ stardict_view_realize (GtkWidget *widget)
 	GdkWindow *window = gdk_window_new (gtk_widget_get_parent_window (widget),
 		&attributes, GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL);
 
-	// The default background colour of the GDK window is transparent,
-	// we'll keep it that way, rather than apply the style context.
-
+	// The default background colour of the GDK window is transparent
 	gtk_widget_register_window (widget, window);
 	gtk_widget_set_window (widget, window);
 	gtk_widget_set_realized (widget, TRUE);
@@ -403,15 +419,33 @@ stardict_view_draw (GtkWidget *widget, cairo_t *cr)
 	GtkAllocation allocation;
 	gtk_widget_get_allocation (widget, &allocation);
 
+	GtkStyleContext *style = gtk_widget_get_style_context (widget);
+	gtk_render_background (style, cr,
+		0, 0, allocation.width, allocation.height);
+	gtk_render_frame (style, cr,
+		0, 0, allocation.width, allocation.height);
+
 	gint offset = -self->top_offset;
 	gint i = self->top_position;
 	for (GList *iter = self->entries; iter; iter = iter->next)
 	{
+		// Style regions would be appropriate, if they weren't deprecated.
+		// GTK+ CSS gadgets/notes are an internal API.  We don't want to turn
+		// this widget into a container, to avoid needless complexity.
+		//
+		// gtk_style_context_{get,set}_path() may be misused by adding the same
+		// GType with gtk_widget_path_append_type() and changing its name
+		// using gtk_widget_path_iter_set_name()... but that is ugly.
+		gtk_style_context_save (style);
+		gtk_style_context_add_class (style, (i++ & 1) ? "even" : "odd");
+
 		cairo_save (cr);
 		cairo_translate (cr, 0, offset);
 		// TODO: later exclude clipped entries, but it's not that important
-		offset += view_entry_draw (iter->data, cr, allocation.width, i++ & 1);
+		offset += view_entry_draw (iter->data, cr, allocation.width, style);
 		cairo_restore (cr);
+
+		gtk_style_context_restore (style);
 	}
 	return TRUE;
 }
@@ -476,6 +510,8 @@ stardict_view_class_init (StardictViewClass *klass)
 	widget_class->size_allocate = stardict_view_size_allocate;
 	widget_class->screen_changed = stardict_view_screen_changed;
 	widget_class->scroll_event = stardict_view_scroll_event;
+
+	gtk_widget_class_set_css_name (widget_class, "stardict-view");
 }
 
 static void