Leave sufficient space for Y-axis value labels

Things look much nicer now that the Y-axis label isn't crashing into
the value labels along the Y axis.

diff --git a/acre.c b/acre.c
index 0851902c51d3b8e4bd029b81fd9c34c7b4a5594a..908bebd74fb15a2921205138f20e19100347b4d9 100644 (file)
--- a/acre.c
+++ b/acre.c
@@ -90,6 +90,11 @@ acre_create (void)
     acre->data_size = 0;
     acre->num_data = 0;
 
+    acre->chart.x = 0;
+    acre->chart.y = 0;
+    acre->chart.width = 0;
+    acre->chart.height = 0;
+
     return acre;
 }
 
@@ -228,6 +233,8 @@ _draw_title_and_labels (acre_t *acre)
     cairo_t *cr = acre->cr;
     PangoFontDescription *title_font;
     PangoLayout *title_layout, *x_axis_layout, *y_axis_layout;
+    PangoLayout *min_y, *max_y;
+    int min_y_width, max_y_width, y_axis_value_width;
     int title_width, title_height;
     int x_axis_width, x_axis_height;
     int y_axis_width, y_axis_height;
@@ -251,14 +258,22 @@ _draw_title_and_labels (acre_t *acre)
     x_axis_layout = _create_layout (acre, acre->x_axis.label);
     y_axis_layout = _create_layout (acre, acre->y_axis.label);
 
+    min_y = _create_layout_printf (acre, "%g",
+                                  round (acre->y_axis.min));
+    max_y = _create_layout_printf (acre, "%g",
+                                  round (acre->y_axis.max));
+
+    pango_layout_get_pixel_size (min_y, &min_y_width, NULL);
+    pango_layout_get_pixel_size (max_y, &max_y_width, NULL);
+    y_axis_value_width = MAX (min_y_width, max_y_width);
+
+    _destroy_layout (min_y);
+    _destroy_layout (max_y);
+
     /* Iterate with the layout of the title and axis labels until they
      * are stable, (this requires iteration since we don't know what
      * to set their widths to in advance due to the wrapping of the
      * other elements). */
-    acre->chart.x = 0;
-    acre->chart.y = 0;
-    acre->chart.width = acre->width;
-    acre->chart.height = acre->height;
     while (1) {
        pango_layout_set_width (title_layout, acre->chart.width * PANGO_SCALE);
        pango_layout_set_width (x_axis_layout, acre->chart.width * PANGO_SCALE);
@@ -269,7 +284,7 @@ _draw_title_and_labels (acre_t *acre)
        pango_layout_get_pixel_size (y_axis_layout, &y_axis_width, &y_axis_height);
 
        new_chart.x = ACRE_PAD + y_axis_height +
-           ACRE_PAD + ACRE_FONT_SIZE;
+           ACRE_PAD + y_axis_value_width;
        new_chart.width = acre->width - acre->chart.x - ACRE_PAD;
 
        new_chart.y = ACRE_PAD + title_height + ACRE_PAD;
@@ -395,6 +410,11 @@ _compute_axis_ranges (acre_t *acre)
     double x_adjust, y_adjust;
     cairo_t *cr = acre->cr;
 
+    acre->x_axis.min = acre->data[0]->points[0].x;
+    acre->x_axis.max = acre->data[0]->points[0].x;
+    acre->y_axis.min = acre->data[0]->points[0].y;
+    acre->y_axis.min = acre->data[0]->points[0].y;
+
     /* First, simply find the extrema of the data. */
     for (d = 0; d < acre->num_data; d++) {
        data = acre->data[d];
@@ -554,7 +574,7 @@ _draw_frame_and_ticks (acre_t *acre)
                    cairo_move_to (cr, acre->x_axis.min, y);
                    cairo_identity_matrix (cr);
                    pango_layout_get_pixel_size (layout, &width, &height);
-                   cairo_rel_move_to (cr, -width-2, -height/2);
+                   cairo_rel_move_to (cr, -width-4, -height/2);
                    _show_layout (cr, layout);
                }
                cairo_restore (cr);
@@ -584,17 +604,25 @@ void
 acre_draw (acre_t *acre, cairo_t *cr, int width, int height)
 {
     acre->cr = cr;
+
     acre->width = width;
     acre->height = height;
 
+    acre->chart.width = width;
+    acre->chart.height = height;
+
     cairo_save (cr);
 
     cairo_set_source_rgb (cr, 1, 1, 1);
 
-    cairo_paint (cr);
+    /* We compute the axis ranges before doing label layout so that we
+     * can account for the width of the y-axis value labels. */
+    _compute_axis_ranges (acre);
 
     _draw_title_and_labels (acre);
 
+    /* And we recompute the axis ranges now that the title and axis
+     * label space is all measured and accounted for. */
     _compute_axis_ranges (acre);
 
     _draw_data (acre);