GtkCssProvider和CSS样式的问题

Question

我正在使用GTK3开发一个简单的程序，并尝试使用GtkCssProvider为特定的小部件（片段）设置CSS样式：

text = gtk_text_view_new();
provider = gtk_css_provider_new();
gtk_css_provider_load_from_data(provider,
                                    "textview {"
                                    "  font-family: serif;"
                                    "  font-size: 30px;"
                                    "  margin-top: 10px;"
                                    "  margin-bottom: 10px;"
                                    "  color: green;"
                                    "}",-1, NULL);
context = gtk_widget_get_style_context(text);
gtk_style_context_add_provider(context,
                                GTK_STYLE_PROVIDER(provider),
                                GTK_STYLE_PROVIDER_PRIORITY_USER);

字体属性设置正确，但边距和颜色不。我没有任何CSS解析错误。如果我使用g_object_set()函数来设置（例如）边距，那么一切工作都很好：

g_object_set(text, "margin-top", 10, NULL);
g_object_set(text, "margin-bottom", 10, NULL);

有什么想法，怎么了？CSS的东西？也许有更好的方法来使用GtkTextView属性（文本和小部件颜色）？我也尝试了GtkInspector工具和直接的CSS编辑，但这对于边距和颜色也不起作用。

Answer 1

显示问题的最小可编译示例（查看边距，取消对57-60行的注释）。用gcc 7.5.0编译。

#include <gtk/gtk.h>
#include <gdk/gdk.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>

static GtkWidget *window;
static GtkWidget* layoutGrid;
static GtkWidget* textLog;
static GtkTextBuffer* bufferLog;
static GtkCssProvider* cssProviderLog;
static GtkStyleContext* context;

gboolean wndDeleteEventHandler(__attribute__((unused)) GtkWidget* widget,
                                __attribute__((unused)) GdkEvent* event,
                                __attribute__((unused)) gpointer user_data)
{
    gtk_main_quit();
    
    return TRUE;
}

int main(int argc, char** argv)
{
    gtk_init(&argc , &argv);
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_default_size(GTK_WINDOW(window), 640, 480);
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    g_signal_connect(window, "delete-event", G_CALLBACK(wndDeleteEventHandler), NULL);

    layoutGrid = gtk_grid_new();
    gtk_widget_set_hexpand(layoutGrid, TRUE);
    gtk_widget_set_vexpand(layoutGrid, TRUE);
    gtk_container_add(GTK_CONTAINER(window), layoutGrid);

    textLog = gtk_text_view_new();
    gtk_widget_set_name(textLog, "textlog");
    bufferLog = gtk_text_view_get_buffer(GTK_TEXT_VIEW (textLog));
    cssProviderLog = gtk_css_provider_new();
    gtk_css_provider_load_from_data(cssProviderLog,
                                    "textview {"
                                    "font-family: serif;"
                                    "font-size: 30px;"
                                    "margin-top: 10px;"
                                    "margin-bottom: 10px;"
                                    "color: green;"
                                    "}",-1, NULL);
    context = gtk_widget_get_style_context(textLog);
    gtk_style_context_add_provider(context,
                                GTK_STYLE_PROVIDER(cssProviderLog),
                                GTK_STYLE_PROVIDER_PRIORITY_USER);
    gtk_text_buffer_set_text(bufferLog, "Hello, this is some text in log buffer", -1);
    gtk_widget_set_hexpand(textLog, TRUE);
    gtk_widget_set_vexpand(textLog, TRUE);
    // g_object_set(textLog, "margin-left", 20, NULL);
    // g_object_set(textLog, "margin-top", 20, NULL);
    // g_object_set(textLog, "margin-bottom", 20, NULL);
    // g_object_set(textLog, "margin-right", 20, NULL);
    gtk_grid_attach(GTK_GRID(layoutGrid), textLog, 0, 0, 1, 1);

    gtk_widget_show_all(window);
    gtk_main();
}

生成文件

C = gcc
CFLAGS = -c

OBJ = \
    screen.o

.c.o:
    $(C) $(CFLAGS) $(INCLUDES) `pkg-config --cflags --libs gtk+-3.0` $<

all: $(OBJ)
    $(C) -o test $(OBJ) `pkg-config --cflags --libs gtk+-3.0`