analyze: plot: place the text on the side with most space

Set the width of the svg to always fit the longest string
while taking its starting position into consideration.

Place the text on the right while the starting point is
in the first half of the screen. After that we put it on
the left to save the svg from being wider that it has to.

1 files changed, 17 insertions, 12 deletions

diff --git a/src/analyze/analyze.c b/src/analyze/analyze.c
index 6bfe13d82d..8730723b86 100644
--- a/src/analyze/analyze.c
+++ b/src/analyze/analyze.c
@@ -509,7 +509,7 @@ static int analyze_plot(sd_bus *bus) {
                 m++;
 
         for (u = times; u < times + n; u++) {
-                double len;
+                double text_start, text_width;
 
                 if (u->ixt < boot->userspace_time ||
                     u->ixt > boot->finish_time) {
@@ -517,10 +517,14 @@ static int analyze_plot(sd_bus *bus) {
                         u->name = NULL;
                         continue;
                 }
-                len = ((boot->firmware_time + u->ixt) * SCALE_X)
-                        + (10.0 * strlen(u->name));
-                if (len > width)
-                        width = len;
+
+                /* If the text cannot fit on the left side then
+                 * increase the svg width so it fits on the right.
+                 * TODO: calculate the text width more accurately */
+                text_width = 8.0 * strlen(u->name);
+                text_start = (boot->firmware_time + u->ixt) * SCALE_X;
+                if (text_width > text_start && text_width + text_start > width)
+                        width = text_width + text_start;
 
                 if (u->iet > u->ixt && u->iet <= boot->finish_time
                                 && u->aet == 0 && u->axt == 0)
@@ -608,7 +612,7 @@ static int analyze_plot(sd_bus *bus) {
         svg_bar("active", boot->userspace_time, boot->finish_time, y);
         svg_bar("generators", boot->generators_start_time, boot->generators_finish_time, y);
         svg_bar("unitsload", boot->unitsload_start_time, boot->unitsload_finish_time, y);
-        svg_text("left", boot->userspace_time, y, "systemd");
+        svg_text(true, boot->userspace_time, y, "systemd");
         y++;
 
         for (u = times; u < times + n; u++) {
@@ -622,7 +626,8 @@ static int analyze_plot(sd_bus *bus) {
                 svg_bar("active",       u->aet, u->axt, y);
                 svg_bar("deactivating", u->axt, u->iet, y);
 
-                b = u->ixt * SCALE_X > width * 2 / 3;
+                /* place the text on the left if we have passed the half of the svg width */
+                b = u->ixt * SCALE_X < width / 2;
                 if (u->time)
                         svg_text(b, u->ixt, y, "%s (%s)",
                                  u->name, format_timespan(ts, sizeof(ts), u->time, USEC_PER_MSEC));
@@ -634,19 +639,19 @@ static int analyze_plot(sd_bus *bus) {
         /* Legend */
         y++;
         svg_bar("activating", 0, 300000, y);
-        svg_text("right", 400000, y, "Activating");
+        svg_text(true, 400000, y, "Activating");
         y++;
         svg_bar("active", 0, 300000, y);
-        svg_text("right", 400000, y, "Active");
+        svg_text(true, 400000, y, "Active");
         y++;
         svg_bar("deactivating", 0, 300000, y);
-        svg_text("right", 400000, y, "Deactivating");
+        svg_text(true, 400000, y, "Deactivating");
         y++;
         svg_bar("generators", 0, 300000, y);
-        svg_text("right", 400000, y, "Generators");
+        svg_text(true, 400000, y, "Generators");
         y++;
         svg_bar("unitsload", 0, 300000, y);
-        svg_text("right", 400000, y, "Loading unit files");
+        svg_text(true, 400000, y, "Loading unit files");
         y++;
 
         svg("</g>\n\n");