gtk - 将一个小的 gtk3 样本从 gtk 3.18 迁移到 gtk 3.22

Question

我正在开发一些应用程序，我们通过调用“gtk_render_option”、“gtk_render_check”等来绘制“RadioButton”、“CheckButton”等小部件。我们的应用程序在 gtk 3.18 上运行良好，但在 gtk 3.22 上，小部件未正确绘制。我已经完成了 3.20 中对主题所做的更改，并尝试在我的应用程序中进行一些更改，但我无法准确理解我需要做什么。

我创建了一个小示例，在其中使用 gtk_render_option API 绘制“RadioButton”。这在 gtk-3.18 中对我来说很好，但在 gtk 3.22 中导致问题。我附上图片和代码以供参考。如果这里有人可以指导我“如何使这个小型演示在 gtk 3.22 上运行”，那就太好了。我应该能够自己处理其余的事情。我可以提供所需的任何进一步信息。

注意：我在 gtk_style_context_add_class API 中尝试了“radio”和“radiobutton”。两者都不适合我。

使用 gtk 3.18 输出

使用 gtk 3.22 输出

代码

#include <string.h>
#include <gtk/gtk.h>

static gboolean
draw_cb_options (GtkWidget *widget, cairo_t *cr)
{
  GtkStyleContext *context;

  context = gtk_widget_get_style_context (widget);

  gtk_style_context_save (context);

  gtk_style_context_add_class (context, "radio");
  gtk_style_context_set_state (context, 0);
  gtk_render_option (context, cr, 10, 50, 40, 40);
  gtk_style_context_set_state (context, GTK_STATE_FLAG_CHECKED);
  gtk_render_option (context, cr, 70, 50, 40, 40);
  gtk_style_context_set_state (context, GTK_STATE_FLAG_INCONSISTENT);
  gtk_render_option (context, cr, 120, 50, 40, 40);
  gtk_style_context_set_state (context, GTK_STATE_FLAG_INSENSITIVE);
  gtk_render_option (context, cr, 170, 50, 40, 40);

  gtk_style_context_restore (context);

  return TRUE;
}


int main (int argc, char *argv[])
{
  GtkWidget *window;
  GtkStyleContext *context;
  gtk_init (&argc, &argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  g_signal_connect (window, "draw", G_CALLBACK (draw_cb_options), NULL);
  gtk_widget_show_all (window);

  gtk_main ();

  return 0;
}

标签： gtkgtk3

Answer 1

根据GTK+ 3.20 更新日志：

GtkDrawingArea 用于在调用 ::draw 处理程序之前隐式渲染主题背景。这已不再是这种情况。如果您依赖主题提供的背景，请gtk_render_background()从 ::draw 处理程序调用。

即使调用gtk_render_backgrounddraw 函数也没有什么区别。下面的示例是基于 gtk3-demo 的外国画图，我尽力简化，但仍然需要经历很多才能完成你需要的。

#include <gtk/gtk.h>
#include <string.h>

static GtkStyleContext *
get_style (GtkStyleContext *parent,
           const char      *selector)
{
  GtkWidgetPath *path;
  GtkStyleContext *context;

  if (parent)
    path = gtk_widget_path_copy (gtk_style_context_get_path (parent));
  else
    path = gtk_widget_path_new ();

  gtk_widget_path_append_type (path, G_TYPE_NONE);
  gtk_widget_path_iter_set_object_name (path, -1, selector);

  context = gtk_style_context_new ();
  gtk_style_context_set_path (context, path);
  gtk_style_context_set_parent (context, parent);
  /* Unfortunately, we have to explicitly set the state again here for it to take effect */
  gtk_style_context_set_state (context, gtk_widget_path_iter_get_state (path, -1));
  gtk_widget_path_unref (path);

  return context;
}

static void
draw_style_common (GtkStyleContext *context,
                   cairo_t         *cr,
                   gint             x,
                   gint             y,
                   gint             width,
                   gint             height,
                   gint            *contents_x,
                   gint            *contents_y,
                   gint            *contents_width,
                   gint            *contents_height)
{
  GtkBorder margin, border, padding;
  int min_width, min_height;

  gtk_style_context_get_margin (context, gtk_style_context_get_state (context), &margin);
  gtk_style_context_get_border (context, gtk_style_context_get_state (context), &border);
  gtk_style_context_get_padding (context, gtk_style_context_get_state (context), &padding);

  gtk_style_context_get (context, gtk_style_context_get_state (context),
                         "min-width", &min_width,
                         "min-height", &min_height,
                         NULL);
  x += margin.left;
  y += margin.top;
  width -= margin.left + margin.right;
  height -= margin.top + margin.bottom;

  width = MAX (width, min_width);
  height = MAX (height, min_height);

  gtk_render_background (context, cr, x, y, width, height);
  gtk_render_frame (context, cr, x, y, width, height);

  if (contents_x)
    *contents_x = x + border.left + padding.left;
  if (contents_y)
    *contents_y = y + border.top + padding.top;
  if (contents_width)
    *contents_width = width - border.left - border.right - padding.left - padding.right;
  if (contents_height)
    *contents_height = height - border.top - border.bottom - padding.top - padding.bottom;
}

static void
query_size (GtkStyleContext *context,
            gint            *width,
            gint            *height)
{
  GtkBorder margin, border, padding;
  int min_width, min_height;

  gtk_style_context_get_margin (context, gtk_style_context_get_state (context), &margin);
  gtk_style_context_get_border (context, gtk_style_context_get_state (context), &border);
  gtk_style_context_get_padding (context, gtk_style_context_get_state (context), &padding);

  gtk_style_context_get (context, gtk_style_context_get_state (context),
                         "min-width", &min_width,
                         "min-height", &min_height,
                         NULL);

  min_width += margin.left + margin.right + border.left + border.right + padding.left + padding.right;
  min_height += margin.top + margin.bottom + border.top + border.bottom + padding.top + padding.bottom;

  *width = MAX (*width, min_width);
  *height = MAX (*height, min_height);
}

static void
draw_radio (GtkWidget     *widget,
            cairo_t       *cr,
            gint           x,
            gint           y,
            GtkStateFlags  state)
{
  GtkStyleContext *button_context, *check_context;
  gint contents_x, contents_y, contents_width, contents_height;
  gint width = 0, height = 0;

  /* This information is taken from the GtkRadioButton docs, see "CSS nodes" */
  button_context = get_style (NULL, "radiobutton");
  check_context = get_style (button_context, "radio");

  gtk_style_context_set_state (check_context, state);

  query_size (button_context, &width, &height);
  query_size (check_context, &width, &height);

  draw_style_common (button_context, cr, x, y, width, height, NULL, NULL, NULL, NULL);
  draw_style_common (check_context, cr, x, y, width, height,
                     &contents_x, &contents_y, &contents_width, &contents_height);
  gtk_render_option (check_context, cr, contents_x, contents_y, contents_width, contents_height);

  g_object_unref (check_context);
  g_object_unref (button_context);

}

static gboolean
draw_cb (GtkWidget *widget,
         cairo_t   *cr)
{
  draw_radio (widget, cr, 10, 10, GTK_STATE_FLAG_NORMAL);
  draw_radio (widget, cr, 50, 50, GTK_STATE_FLAG_CHECKED);
  draw_radio (widget, cr, 100, 100, GTK_STATE_FLAG_INCONSISTENT);
  draw_radio (widget, cr, 150, 150, GTK_STATE_FLAG_INSENSITIVE);

  return FALSE;
}

int main (int argc, char *argv[])
{
  GtkWidget *box, *window, *da;

  gtk_init (&argc, &argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
  gtk_container_add (GTK_CONTAINER (window), box);

  g_signal_connect (box, "draw", G_CALLBACK (draw_cb), NULL);

  gtk_widget_show_all (window);
  gtk_main ();

  return 0;
}