Use function pointers for object rendering and overlays

1 files changed, 202 insertions, 27 deletions

diff --git a/src/tool_text.c b/src/tool_text.c
index 9419a12..4881fec 100644
--- a/src/tool_text.c
+++ b/src/tool_text.c
@@ -34,33 +34,6 @@
 #include "mainwindow.h"
 
 
-struct object *add_text_object(struct slide *s, double x, double y,
-                               struct style *sty)
-{
-	struct object *new;
-
-	new = new_object(TEXT, sty);
-
-	new->x = x;  new->y = y;
-	new->bb_width = 10.0;
-	new->bb_height = 40.0;
-	new->text = malloc(1);
-	new->text[0] = '\0';
-	new->text_len = 1;
-	new->insertion_point = 0;
-	new->layout = NULL;
-	new->fontdesc = NULL;
-
-	if ( add_object_to_slide(s, new) ) {
-		free_object(new);
-		return NULL;
-	}
-	s->object_seq++;
-
-	return new;
-}
-
-
 void insert_text(struct object *o, char *t)
 {
 	char *tmp;
@@ -201,3 +174,205 @@ void position_caret(struct object *o, double x, double y)
 
 	o->insertion_point = idx+trail;
 }
+
+
+static void calculate_size_from_style(struct object *o,
+                                      double *peright, double *pebottom,
+                                      double *pmw, double *pmh)
+{
+	double max_width, max_height;
+	double ebottom, eright, mw, mh;
+
+	eright = o->parent->parent->slide_width - o->style->margin_right;
+	ebottom = o->parent->parent->slide_height - o->style->margin_bottom;
+	mw = o->parent->parent->slide_width;
+	mh = o->parent->parent->slide_height;
+
+	*peright = eright;  *pebottom = ebottom;
+	*pmw = mw;  *pmh = mh;
+
+	max_width = mw - o->style->margin_left - o->style->margin_right;
+
+	/* Use the provided maximum width if it exists and is smaller */
+	if ( o->style->use_max_width && (o->style->max_width < max_width) )
+	{
+		max_width = o->style->max_width;
+	}
+
+	max_height = mh - o->style->margin_top - o->style->margin_bottom;
+
+	pango_layout_set_width(o->layout, max_width*PANGO_SCALE);
+	pango_layout_set_height(o->layout, max_height*PANGO_SCALE);
+	pango_layout_set_wrap(o->layout, PANGO_WRAP_WORD_CHAR);
+	pango_layout_set_ellipsize(o->layout, PANGO_ELLIPSIZE_MIDDLE);
+
+	switch ( o->style->halign ) {
+	case J_LEFT :
+		pango_layout_set_alignment(o->layout, PANGO_ALIGN_LEFT);
+		break;
+	case J_RIGHT :
+		pango_layout_set_alignment(o->layout, PANGO_ALIGN_RIGHT);
+		break;
+	case J_CENTER :
+		pango_layout_set_alignment(o->layout, PANGO_ALIGN_CENTER);
+		break;
+	}
+}
+
+
+static void calculate_position_from_style(struct object *o,
+                                          double eright, double ebottom,
+                                          double mw, double mh,
+                                          double *pxo, double *pyo)
+{
+	double xo, yo;
+	PangoRectangle ink, logical;
+
+	pango_layout_get_extents(o->layout, &ink, &logical);
+	xo = ink.x/PANGO_SCALE;  yo = logical.y/PANGO_SCALE;
+
+	switch ( o->style->halign ) {
+	case J_LEFT :
+		o->x = -xo + o->style->margin_left;
+		break;
+	case J_RIGHT :
+		o->x = -xo + eright - o->bb_width;
+		break;
+	case J_CENTER :
+		o->x = mw/2.0 - o->bb_width/2.0 - xo + o->style->offset_x;
+		break;
+	}
+
+	if ( o->style->halign == J_CENTER )
+	{
+		if ( o->x+xo < o->style->margin_left ) {
+			o->x = o->style->margin_left - xo;
+		}
+
+		if ( o->x+xo + o->bb_width > mw-o->style->margin_right ) {
+			o->x = mw-o->style->margin_right - xo - o->bb_width;
+		}
+	}
+
+	switch ( o->style->valign ) {
+	case V_TOP :
+		o->y = o->style->margin_top;
+		break;
+	case V_BOTTOM :
+		o->y = ebottom - o->bb_height;
+		break;
+	case V_CENTER :
+		o->y = mh/2.0 - o->bb_height/2.0 + yo - o->style->offset_y;
+		break;
+	}
+
+	if ( o->style->valign == V_CENTER ) {
+
+		if ( o->y < o->style->margin_top ) {
+			o->y = o->style->margin_top;
+		}
+
+		if ( o->y+yo + o->bb_height > mh - o->style->margin_bottom ) {
+			o->y = mh-o->style->margin_bottom - yo - o->bb_height;
+		}
+	}
+
+	*pxo = xo;  *pyo = yo;
+}
+
+
+static void render_text_object(cairo_t *cr, struct object *o)
+{
+	PangoRectangle ink, logical;
+	double eright = 0.0;
+	double ebottom = 0.0;
+	double mw = 0.0;
+	double mh = 0.0;
+	double xo, yo;
+	int furniture = 0;
+	GdkColor col;
+
+	furniture = o->style != o->parent->parent->ss->styles[0];
+
+	o->layout = pango_cairo_create_layout(cr);
+	pango_layout_set_text(o->layout, o->text, -1);
+	o->fontdesc = pango_font_description_from_string(o->style->font);
+	pango_layout_set_font_description(o->layout, o->fontdesc);
+
+	if ( furniture ) {
+		calculate_size_from_style(o, &eright, &ebottom, &mw, &mh);
+	} else {
+		pango_layout_set_alignment(o->layout, PANGO_ALIGN_LEFT);
+	}
+
+	pango_cairo_update_layout(cr, o->layout);
+	pango_layout_get_extents(o->layout, &ink, &logical);
+	o->bb_width = ink.width / PANGO_SCALE;
+	o->bb_height = logical.height/PANGO_SCALE;
+
+	if ( furniture ) {
+		calculate_position_from_style(o, eright, ebottom,
+		                              mw, mh, &xo, &yo);
+	}
+
+	cairo_move_to(cr, o->x, o->y);
+	gdk_color_parse(o->style->colour, &col);
+	gdk_cairo_set_source_color(cr, &col);  /* FIXME: Honour alpha as well */
+	pango_cairo_show_layout(cr, o->layout);
+
+	if ( furniture ) {
+		o->x += xo;
+		o->y += yo;
+	}
+}
+
+
+static void draw_caret(cairo_t *cr, struct object *o)
+{
+	int line, xpos;
+	double xposd;
+
+	assert(o->type == TEXT);
+
+	pango_layout_index_to_line_x(o->layout, o->insertion_point,
+	                             0, &line, &xpos);
+
+	xposd = xpos/PANGO_SCALE;
+
+	cairo_move_to(cr, o->x+xposd, o->y);
+	cairo_line_to(cr, o->x+xposd, o->y+o->bb_height);
+	cairo_set_source_rgb(cr, 1.0, 0.5, 0.0);
+	cairo_set_line_width(cr, 2.0);
+	cairo_stroke(cr);
+}
+
+
+struct object *add_text_object(struct slide *s, double x, double y,
+                               struct style *sty)
+{
+	struct object *new;
+
+	new = new_object(TEXT, sty);
+
+	new->x = x;  new->y = y;
+	new->bb_width = 10.0;
+	new->bb_height = 40.0;
+	new->text = malloc(1);
+	new->text[0] = '\0';
+	new->text_len = 1;
+	new->insertion_point = 0;
+	new->layout = NULL;
+	new->fontdesc = NULL;
+
+	/* Methods for this object */
+	new->render_object = render_text_object;
+	new->draw_editing_overlay = draw_caret;
+
+	if ( add_object_to_slide(s, new) ) {
+		free_object(new);
+		return NULL;
+	}
+	s->object_seq++;
+
+	return new;
+}