added "Zoom" button and improved scaling

It should be possible to have a certain limit where we
stop zooming so that short dives are visible as such
at first glance. Therefore a "Zoom" button has been
added to the "Log" menu along with a shortcut (Ctrl + "0").
The user can now zoom/unzoom the plot and is still able to
quickly distinguish short dives from normal ones when
browsing the log.

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>

gtk-gui.c

@@ -22,6 +22,7 @@ GtkWidget *error_info_bar;
 GtkWidget *error_label;
 GtkWidget *vpane, *hpane;
 int        error_count;
+extern char zoomed_plot;
 
 const char *divelist_font;
 
@@ -610,6 +611,13 @@ static void view_three(GtkWidget *w, gpointer data)
 	gtk_paned_set_position(GTK_PANED(vpane), 200);
 }
 
+static void toggle_zoom(GtkWidget *w, gpointer data)
+{
+	zoomed_plot = (zoomed_plot)?0 : 1;
+	/*Update dive*/
+	repaint_dive();
+}
+
 static GtkActionEntry menu_items[] = {
 	{ "FileMenuAction", GTK_STOCK_FILE, "File", NULL, NULL, NULL},
 	{ "LogMenuAction",  GTK_STOCK_FILE, "Log", NULL, NULL, NULL},
@@ -629,6 +637,7 @@ static GtkActionEntry menu_items[] = {
 	{ "ViewProfile",    NULL, "Profile", CTRLCHAR "2", NULL, G_CALLBACK(view_profile) },
 	{ "ViewInfo",       NULL, "Info", CTRLCHAR "3", NULL, G_CALLBACK(view_info) },
 	{ "ViewThree",      NULL, "Three", CTRLCHAR "4", NULL, G_CALLBACK(view_three) },
+	{ "ToggleZoom",     NULL, "Toggle Zoom", CTRLCHAR "0", NULL, G_CALLBACK(toggle_zoom) },
 };
 static gint nmenu_items = sizeof (menu_items) / sizeof (menu_items[0]);
 
@@ -648,6 +657,7 @@ static const gchar* ui_string = " \
 				<menuitem name=\"Import\" action=\"Import\" /> \
 				<separator name=\"Separator\"/> \
 				<menuitem name=\"Renumber\" action=\"Renumber\" /> \
+				<menuitem name=\"Toggle Zoom\" action=\"ToggleZoom\" /> \
 				<menu name=\"View\" action=\"ViewMenuAction\"> \
 					<menuitem name=\"List\" action=\"ViewList\" /> \
 					<menuitem name=\"Profile\" action=\"ViewProfile\" /> \

profile.c

@@ -14,6 +14,7 @@
 #include "color.h"
 
 int selected_dive = 0;
+char zoomed_plot = 0;
 
 typedef enum { STABLE, SLOW, MODERATE, FAST, CRAZY } velocity_t;
 
@@ -180,18 +181,24 @@ static void dump_pi (struct plot_info *pi)
  * When showing dive profiles, we scale things to the
  * current dive. However, we don't scale past less than
  * 30 minutes or 90 ft, just so that small dives show
- * up as such.
+ * up as such unless zoom is enabled.
- * If the dive time is shorter than 10 minutes we assume that
+ * We also need to add 180 seconds at the end so the min/max
- * this has been an apnea dive and display it accordingly.
- * we also need to add 180 seconds at the end so the min/max
  * plots correctly
  */
 static int get_maxtime(struct plot_info *pi)
 {
 	int seconds = pi->maxtime;
-	if (seconds < 600) {
+	if (zoomed_plot) {
-		/* Possible apnea dive, we scale accordingly */
+		/* Rounded up to one minute, with at least 2.5 minutes to
+		 * spare.
+		 * For dive times shorter than 10 minutes, we use seconds/4 to
+		 * calculate the space dynamically.
+		 * This is seamless since 600/4 = 150.
+		 */
+		if ( seconds < 600 )
 			return ROUND_UP(seconds+seconds/4, 60);
+		else
+			return ROUND_UP(seconds+150, 60);
 	} else {
 		/* min 30 minutes, rounded up to 5 minutes, with at least 2.5 minutes to spare */
 		return MAX(30*60, ROUND_UP(seconds+150, 60*5));
@@ -201,9 +208,14 @@ static int get_maxtime(struct plot_info *pi)
 static int get_maxdepth(struct plot_info *pi)
 {
 	unsigned mm = pi->maxdepth;
+	if (zoomed_plot) {
+		/* Rounded up to 10m, with at least 3m to spare */
+		return ROUND_UP(mm+3000, 10000);
+	} else {
 		/* Minimum 30m, rounded up to 10m, with at least 3m to spare */
 		return MAX(30000, ROUND_UP(mm+3000, 10000));
 	}
+}
 
 typedef struct {
 	int size;
@@ -450,27 +462,21 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
 	int sec, depth;
 	struct plot_data *entry;
 	int maxtime, maxdepth, marker;
-	int increments[4] = { 5*60, 10*60, 15*60, 30*60 };
+	int increments[8] = { 10, 20, 30, 60, 5*60, 10*60, 15*60, 30*60 };
 
 	/* Get plot scaling limits */
 	maxtime = get_maxtime(pi);
 	maxdepth = get_maxdepth(pi);
-	/* We check whether this has been an apnea dive and overwrite
+
-	* the increments in order to get reasonable time markers */
+	/* Time markers: at most every 5 min, but no more than 12 markers.
-	if (maxtime < 600) {
+	 * We start out with 10 seconds and increment up to 30 minutes,
-		increments[0] = 10;
+	 * depending on the dive time.
-		increments[1] = 20;
-		increments[2] = 30;
-		increments[3] = 60;
-	}
-	/* Time markers: at most every 5 min, but no more than 12 markers
-	 * and for convenience we do 5, 10, 15 or 30 min intervals.
 	 * This allows for 6h dives - enough (I hope) for even the craziest
 	 * divers - but just in case, for those 8h depth-record-breaking dives,
 	 * we double the interval if this still doesn't get us to 12 or fewer
 	 * time markers */
 	i = 0;
-	while (maxtime / increments[i] > 12 && i < 4)
+	while (maxtime / increments[i] > 12 && i < 8)
 		i++;
 	incr = increments[i];
 	while (maxtime / incr > 12)
@@ -490,7 +496,7 @@ static void plot_depth_profile(struct graphics_context *gc, struct plot_info *pi
 	/* now the text on the time markers */
 	text_render_options_t tro = {10, TIME_TEXT, CENTER, TOP};
 	if (maxtime < 600) {
-		/* Be a bit more verbose with shorter (apnea) dives */
+		/* Be a bit more verbose with shorter dives */
 		for (i = incr; i < maxtime; i += incr)
 			plot_text(gc, &tro, i, 1, "%d:%d", i/60, i%60);
 	} else {