Add slide rendering machinery

6 files changed, 207 insertions, 8 deletions

diff --git a/Makefile.am b/Makefile.am
index 16462c2..d8cf801 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -8,11 +8,12 @@ AM_CFLAGS = -Wall
 AM_CPPFLAGS = -DDATADIR=\""$(datadir)"\" -I$(top_builddir)/lib -I$(top_srcdir)/lib
 LDADD = $(top_builddir)/lib/libgnu.a @IGNORE_UNUSED_LIBRARIES_CFLAGS@
 
-src_colloquium_SOURCES = src/colloquium.c src/presentation.c src/mainwindow.c
+src_colloquium_SOURCES = src/colloquium.c src/presentation.c src/mainwindow.c \
+                         src/slide_render.c
 
 INCLUDES = "-I$(top_srcdir)/data"
 
-EXTRA_DIST += src/presentation.h src/mainwindow.h
+EXTRA_DIST += src/presentation.h src/mainwindow.h src/slide_render.h
 
 colloquiumdir = $(datadir)/colloquium
 colloquium_DATA = data/colloquium.ui
diff --git a/src/mainwindow.c b/src/mainwindow.c
index b118328..289a096 100644
--- a/src/mainwindow.c
+++ b/src/mainwindow.c
@@ -28,9 +28,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include <gtk/gtk.h>
+#include <assert.h>
 
 #include "presentation.h"
 #include "mainwindow.h"
+#include "slide_render.h"
 
 
 static void add_ui_sig(GtkUIManager *ui, GtkWidget *widget,
@@ -136,6 +138,15 @@ static gint close_sig(GtkWidget *window, struct presentation *p)
 }
 
 
+static gboolean button_press_sig(GtkWidget *da, GdkEventButton *event,
+                                 struct presentation *p)
+{
+	printf("%f %f\n", event->x - p->border_offs_x,
+	                  event->y - p->border_offs_y);
+	return 0;
+}
+
+
 static gboolean expose_sig(GtkWidget *da, GdkEventExpose *event,
                            struct presentation *p)
 {
@@ -155,10 +166,15 @@ static gboolean expose_sig(GtkWidget *da, GdkEventExpose *event,
 	gtk_widget_get_allocation(da, &allocation);
 	xoff = (allocation.width - p->slide_width)/2.0;
 	yoff = (allocation.height - p->slide_height)/2.0;
+	p->border_offs_x = xoff;  p->border_offs_y = yoff;
 
 	cairo_translate(cr, xoff, yoff);
-	cairo_rectangle(cr, 0.0, 0.0, p->slide_width, p->slide_height);
-	cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
+
+	/* Draw the slide from the cache */
+	cairo_rectangle(cr, event->area.x, event->area.y,
+	                event->area.width, event->area.height);
+	cairo_set_source_surface(cr, p->slides[p->view_slide]->render_cache,
+	                         0.0, 0.0);
 	cairo_fill(cr);
 
 	cairo_destroy(cr);
@@ -167,6 +183,15 @@ static gboolean expose_sig(GtkWidget *da, GdkEventExpose *event,
 }
 
 
+static void check_redraw_slide(struct presentation *p, int n)
+{
+	/* Update necessary? */
+	if ( p->slides[n]->object_seq <= p->slides[n]->render_cache_seq ) return;
+
+	render_slide(p->slides[n]);
+}
+
+
 int open_mainwindow(struct presentation *p)
 {
 	GtkWidget *window;
@@ -205,12 +230,23 @@ int open_mainwindow(struct presentation *p)
 	                            p->slide_width + 20,
 	                            p->slide_height + 20);
 
+	gtk_widget_set_can_focus(GTK_WIDGET(p->drawingarea), TRUE);
+	gtk_widget_add_events(GTK_WIDGET(p->drawingarea),
+	                      GDK_POINTER_MOTION_HINT_MASK
+	                       | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK
+	                       | GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK);
+	g_signal_connect(GTK_OBJECT(p->drawingarea), "button-press-event",
+			 G_CALLBACK(button_press_sig), p);
+
 	g_signal_connect(GTK_OBJECT(p->drawingarea), "expose-event",
 			 G_CALLBACK(expose_sig), p);
 
 	gtk_window_set_default_size(GTK_WINDOW(p->window), 1024+100, 768+100);
 	gtk_window_set_resizable(GTK_WINDOW(p->window), TRUE);
 
+	assert(p->num_slides > 0);
+	check_redraw_slide(p, p->view_slide);
+
 	gtk_widget_show_all(window);
 	return 0;
 }
diff --git a/src/presentation.c b/src/presentation.c
index 8a5dca7..b67c8fd 100644
--- a/src/presentation.c
+++ b/src/presentation.c
@@ -29,6 +29,38 @@
 #include <string.h>
 
 #include "presentation.h"
+#include "slide_render.h"
+
+
+int add_slide(struct presentation *p)
+{
+	struct slide **try;
+	struct slide *new;
+
+	try = realloc(p->slides, p->num_slides*sizeof(struct slide **));
+	if ( try == NULL ) return 1;
+	p->slides = try;
+
+	new = malloc(sizeof(struct slide));
+	if ( new == NULL ) return 1;
+	/* Doesn't matter that p->slides now has some excess space -
+	 * it'll get corrected the next time a slide is added or deleted. */
+
+	/* No objects to start with */
+	new->n_objects = 0;
+	new->object_seq = 0;
+	new->objects = NULL;
+
+	new->slide_width = p->slide_width;
+	new->slide_height = p->slide_height;
+
+	new->render_cache_seq = 0;
+	new->render_cache = NULL;
+	render_slide(new);  /* Render nothing, just to make the surface exist */
+
+	p->slides[p->num_slides++] = new;
+	return 0;
+}
 
 
 struct presentation *new_presentation()
@@ -47,5 +79,11 @@ struct presentation *new_presentation()
 	new->slide_width = 1024.0;
 	new->slide_height = 768.0;
 
+	new->num_slides = 0;
+	new->slides = NULL;
+	add_slide(new);
+
+	new->view_slide = 0;
+
 	return new;
 }
diff --git a/src/presentation.h b/src/presentation.h
index 14829c7..5b219a2 100644
--- a/src/presentation.h
+++ b/src/presentation.h
@@ -31,18 +31,52 @@
 #include <gtk/gtk.h>
 
 
+enum objtype
+{
+	RECTANGLE,
+};
+
+
+struct object
+{
+	enum objtype type;
+};
+
+
+struct slide
+{
+	cairo_surface_t *render_cache;
+	int              render_cache_seq;
+
+	int              n_objects;
+	struct object   *objects;
+	int              object_seq;
+
+	double           slide_width;
+	double           slide_height;
+};
+
+
 struct presentation
 {
-	char *titlebar;
-	char *filename;
+	char            *titlebar;
+	char            *filename;
 
 	GtkWidget       *window;
 	GtkWidget	*drawingarea;
 	GtkUIManager	*ui;
 	GtkActionGroup	*action_group;
 
-	double slide_width;
-	double slide_height;
+	double           slide_width;
+	double           slide_height;
+	double           border_offs_x;
+	double           border_offs_y;
+
+	/* The slide currently being displayed */
+	unsigned int     view_slide;
+
+	unsigned int     num_slides;
+	struct slide   **slides;
 };
 
 
diff --git a/src/slide_render.c b/src/slide_render.c
new file mode 100644
index 0000000..1966fe7
--- /dev/null
+++ b/src/slide_render.c
@@ -0,0 +1,54 @@
+/*
+ * slide_render.c
+ *
+ * Colloquium - A tiny presentation program
+ *
+ * Copyright (c) 2011 Thomas White <taw@bitwiz.org.uk>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cairo.h>
+
+#include "slide_render.h"
+#include "presentation.h"
+
+
+int render_slide(struct slide *s)
+{
+	cairo_surface_t *surf;
+	cairo_t *cr;
+
+	surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
+	                                  s->slide_width, s->slide_height);
+
+	cr = cairo_create(surf);
+
+	cairo_rectangle(cr, 0.0, 0.0, s->slide_width, s->slide_height);
+	cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
+	cairo_fill(cr);
+
+	cairo_destroy(cr);
+
+	if ( s->render_cache != NULL ) cairo_surface_destroy(s->render_cache);
+	s->render_cache = surf;
+
+	return 0;
+}
diff --git a/src/slide_render.h b/src/slide_render.h
new file mode 100644
index 0000000..500a3ed
--- /dev/null
+++ b/src/slide_render.h
@@ -0,0 +1,36 @@
+/*
+ * slide_render.h
+ *
+ * Colloquium - A tiny presentation program
+ *
+ * Copyright (c) 2011 Thomas White <taw@bitwiz.org.uk>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef SLIDE_RENDER_H
+#define SLIDE_RENDER_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include "presentation.h"
+
+extern int render_slide(struct slide *s);
+
+
+#endif	/* SLIDE_RENDER_H */