[planner: 16/32] charts: Port font width factor updating to GtkStyleContext

[Mart Raudsepp <mraudsepp src gnome org>]

commit 5de6777104cf85f1773e467932a8978fb6e357a2
Author: Mart Raudsepp <leio gentoo org>
Date:   Mon May 31 00:17:56 2021 +0300

    charts: Port font width factor updating to GtkStyleContext
    
    In the process be more verbose with the static variable name and sync the
    different chart code with eachother, adding missing re-layout in one case,
    and measuring the correct canvas font in the other case.

 src/planner-gantt-chart.c | 31 ++++++++++++-------------------
 src/planner-usage-chart.c | 41 +++++++++++++++++++----------------------
 2 files changed, 31 insertions(+), 41 deletions(-)
---
diff --git a/src/planner-gantt-chart.c b/src/planner-gantt-chart.c
index 36a12f77..2d69d9b0 100644
--- a/src/planner-gantt-chart.c
+++ b/src/planner-gantt-chart.c
@@ -47,11 +47,11 @@
 #define ZOOM_OUT_LIMIT 0
 
 #define DEFAULT_ZOOM_LEVEL 7
-#define SCALE(n) (f*pow(2,(n)-19))
-#define ZOOM(x) (log((x)/f)/log(2)+19)
+#define SCALE(n) (font_width_factor*pow(2,(n)-19))
+#define ZOOM(x) (log((x)/font_width_factor)/log(2)+19)
 
 /* Font width factor. */
-static gdouble f = 1.0;
+static gdouble font_width_factor = 1.0;
 
 #define CRITICAL_PATH_KEY  "highlight-critical-path"
 #define NOSTDDAYS_PATH_KEY "display-nonstandard-days"
@@ -151,8 +151,7 @@ static void        gantt_chart_get_property             (GObject            *obj
                                                         GValue             *value,
                                                         GParamSpec         *pspec);
 static void        gantt_chart_destroy                  (GtkWidget          *widget);
-static void        gantt_chart_style_set                (GtkWidget          *widget,
-                                                        GtkStyle           *prev_style);
+static void        gantt_chart_style_updated            (GtkWidget          *widget);
 static void        gantt_chart_realize                  (GtkWidget          *widget);
 static void        gantt_chart_unrealize                (GtkWidget          *widget);
 static void        gantt_chart_map                      (GtkWidget          *widget);
@@ -277,7 +276,7 @@ gantt_chart_class_init (PlannerGanttChartClass *class)
        o_class->finalize     = gantt_chart_finalize;
 
        widget_class->destroy       = gantt_chart_destroy;
-       widget_class->style_set     = gantt_chart_style_set;
+       widget_class->style_updated = gantt_chart_style_updated;
        widget_class->realize       = gantt_chart_realize;
        widget_class->map           = gantt_chart_map;
        widget_class->unrealize     = gantt_chart_unrealize;
@@ -537,36 +536,30 @@ gantt_chart_destroy (GtkWidget *widget)
 }
 
 static void
-gantt_chart_style_set (GtkWidget *widget,
-                      GtkStyle  *prev_style)
+gantt_chart_style_updated (GtkWidget *widget)
 {
        PlannerGanttChart     *chart;
-       PlannerGanttChartPriv *priv;
        PangoContext     *context;
        PangoFontMetrics *metrics;
 
        g_return_if_fail (PLANNER_IS_GANTT_CHART (widget));
 
-       if (GTK_WIDGET_CLASS (parent_class)->style_set) {
-               GTK_WIDGET_CLASS (parent_class)->style_set (widget,
-                                                           prev_style);
+       if (GTK_WIDGET_CLASS (parent_class)->style_updated) {
+               GTK_WIDGET_CLASS (parent_class)->style_updated (widget);
        }
 
        chart = PLANNER_GANTT_CHART (widget);
-       priv = chart->priv;
 
-       context = gtk_widget_get_pango_context (widget);
+       context = gtk_widget_get_pango_context (GTK_WIDGET (chart->priv->canvas));
 
-       metrics = pango_context_get_metrics (context,
-                                            gtk_widget_get_style (widget)->font_desc,
-                                            NULL);
+       metrics = pango_context_get_metrics (context, NULL, NULL);
 
-       f = 0.2 * pango_font_metrics_get_approximate_char_width (metrics) / PANGO_SCALE;
+       font_width_factor = 0.2 * pango_font_metrics_get_approximate_char_width (metrics) / PANGO_SCALE;
 
        pango_font_metrics_unref(metrics);
 
        /* Re-layout with the new factor. */
-       gantt_chart_set_zoom (PLANNER_GANTT_CHART (widget), priv->zoom);
+       gantt_chart_set_zoom (PLANNER_GANTT_CHART (widget), chart->priv->zoom);
 }
 
 static void
diff --git a/src/planner-usage-chart.c b/src/planner-usage-chart.c
index 32e3c06d..d88e549c 100644
--- a/src/planner-usage-chart.c
+++ b/src/planner-usage-chart.c
@@ -48,11 +48,11 @@
 #define ZOOM_OUT_LIMIT 0
 
 #define DEFAULT_ZOOM_LEVEL 7
-#define SCALE(n) (f*pow(2,(n)-19))
-#define ZOOM(x) (log((x)/f)/log(2)+19)
+#define SCALE(n) (font_width_factor*pow(2,(n)-19))
+#define ZOOM(x) (log((x)/font_width_factor)/log(2)+19)
 
 /* Font width factor. */
-static gdouble f = 1.0;
+static gdouble font_width_factor = 1.0;
 
 typedef struct _TreeNode TreeNode;
 typedef void (*TreeFunc) (TreeNode *node, gpointer data);
@@ -130,8 +130,7 @@ static void      usage_chart_get_property          (GObject                 *obj
 static void      usage_chart_set_zoom              (PlannerUsageChart      *chart,
                                                     gdouble                  level);
 static void      usage_chart_destroy               (GtkWidget               *widget);
-static void      usage_chart_style_set             (GtkWidget               *widget,
-                                                    GtkStyle                *prev_style);
+static void      usage_chart_style_updated         (GtkWidget               *widget);
 static void      usage_chart_realize               (GtkWidget               *widget);
 static void      usage_chart_map                   (GtkWidget               *widget);
 static void      usage_chart_unrealize             (GtkWidget               *widget);
@@ -258,7 +257,7 @@ usage_chart_class_init (PlannerUsageChartClass * class)
        o_class->finalize = usage_chart_finalize;
 
        widget_class->destroy = usage_chart_destroy;
-       widget_class->style_set = usage_chart_style_set;
+       widget_class->style_updated = usage_chart_style_updated;
        widget_class->realize = usage_chart_realize;
        widget_class->map = usage_chart_map;
        widget_class->unrealize = usage_chart_unrealize;
@@ -652,30 +651,28 @@ usage_chart_destroy (GtkWidget *widget)
 }
 
 static void
-usage_chart_style_set (GtkWidget *widget, GtkStyle *prev_style)
+usage_chart_style_updated (GtkWidget *widget)
 {
-       PlannerUsageChart     *chart;
-       PlannerUsageChartPriv *priv;
-       GtkWidget              *canvas;
-       PangoContext           *context;
-       PangoFontMetrics       *metrics;
+       PlannerUsageChart *chart;
+       PangoContext      *context;
+       PangoFontMetrics  *metrics;
 
-       if (GTK_WIDGET_CLASS (parent_class)->style_set) {
-               GTK_WIDGET_CLASS (parent_class)->style_set (widget,
-                                                           prev_style);
+       if (GTK_WIDGET_CLASS (parent_class)->style_updated) {
+               GTK_WIDGET_CLASS (parent_class)->style_updated (widget);
        }
 
        chart = PLANNER_USAGE_CHART (widget);
-       priv = chart->priv;
 
-       canvas = GTK_WIDGET (priv->canvas);
+       context = gtk_widget_get_pango_context (GTK_WIDGET (chart->priv->canvas));
+
+       metrics = pango_context_get_metrics (context, NULL, NULL);
+
+       font_width_factor = 0.2 * pango_font_metrics_get_approximate_char_width (metrics) / PANGO_SCALE;
 
-       context = gtk_widget_get_pango_context (canvas);
-       metrics = pango_context_get_metrics (context,
-                                            gtk_widget_get_style (canvas)->font_desc, NULL);
-       f = 0.2 * pango_font_metrics_get_approximate_char_width (metrics) /
-               PANGO_SCALE;
        pango_font_metrics_unref(metrics);
+
+       /* Re-layout with the new factor. */
+       usage_chart_set_zoom (PLANNER_USAGE_CHART (widget), chart->priv->zoom);
 }
 
 static void