GTK 按键事件传播导致递归或不起作用
GTK keypress event propagation either causes recursion or does not work
我有一个简单的 GTK 程序,在 window 中包含一个 webkit2 小部件,仅此而已。我希望能够过滤进入 webkit2 小部件的按键。起初我向 webkit 小部件添加了一个键掩码并添加了一个回调函数,但是在回调函数中传播事件后它只是递归地调用自身导致崩溃。为了解决这个问题,我将我的键掩码附加到 main-window,它是我的 webkit 小部件的父级,但这不再阻止输入停止,有时键释放事件会递归地相互调用。我想知道如何实现我的目标? (我使用了 GTK+ 输入事件处理文档页面中提到的所有不同类型的传播。)
当前密钥掩码:
gtk_widget_add_events(GTK_WIDGET(main_window), GDK_KEY_PRESS_MASK);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_release_event", G_CALLBACK(keypressHandeler), NULL);
当前回调函数(return 只是为了查看此时传播是否有效)
gboolean keypressHandeler(GtkWidget *widget, GdkEventKey *event, gpointer data){
if(event->type == GDK_KEY_PRESS)
printf("Key press\n");
if(event->type == GDK_KEY_RELEASE)
printf("Key release\n");
return gtk_widget_event(GTK_WIDGET(webView), event);
}
你的代码中的问题是你手动模拟信号通过
gtk_widget_event() (https://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-event)
因此在第一次调用 keypressHandeler 后 gtk_widget_event 将再次模拟相同的事件,因此它将 运行 进入无限循环。
如果您 return 在 "keypressHandeler" 中为 false 或 true,您的代码将有效
#include <gtk/gtk.h>
#include <webkit2/webkit2.h>
WebKitWebView *webView;
gboolean keypressHandeler(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
if (event->type == GDK_KEY_PRESS)
printf("Key press from mainwindow\n");
if (event->type == GDK_KEY_RELEASE)
printf("Key release\n");
//for the key use want to propogate
if (dont wanna propogate )
{
return TRUE;
} else {
return FALSE;
}
}
gboolean keypressHandeler2(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
if (event->type == GDK_KEY_PRESS)
printf("Key press from webkit\n");
if (event->type == GDK_KEY_RELEASE)
printf("Key release\n");
// set it as TRUE to stop porpogation.. (for some reason it propogating to mainwindow once)
return TRUE;
}
static void destroyWindowCb(GtkWidget* widget, GtkWidget* window);
static gboolean closeWebViewCb(WebKitWebView* webView, GtkWidget* window);
int main(int argc, char* argv[])
{
// Initialize GTK+
gtk_init(&argc, &argv);
// Create an 800x600 window that will contain the browser instance
GtkWidget *main_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size(GTK_WINDOW(main_window), 800, 600);
// Create a browser instance
webView = WEBKIT_WEB_VIEW(webkit_web_view_new());
// Put the browser area into the main window
gtk_container_add(GTK_CONTAINER(main_window), GTK_WIDGET(webView));
// Set up callbacks so that if either the main window or the browser instance is
// closed, the program will exit
gtk_widget_add_events(GTK_WIDGET(main_window), GDK_KEY_PRESS_MASK);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(webView)), "key_press_event", G_CALLBACK(keypressHandeler2), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_release_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(webView)), "key_release_event", G_CALLBACK(keypressHandeler2), NULL);
g_signal_connect(main_window, "destroy", G_CALLBACK(destroyWindowCb), NULL);
g_signal_connect(webView, "close", G_CALLBACK(closeWebViewCb), main_window);
// Load a web page into the browser instance
webkit_web_view_load_uri(webView, "http://www.webkitgtk.org/");
// Make sure that when the browser area becomes visible, it will get mouse
// and keyboard events
gtk_widget_grab_focus(GTK_WIDGET(webView));
// Make sure the main window and all its contents are visible
gtk_widget_show_all(main_window);
// Run the main GTK+ event loop
gtk_main();
return 0;
}
static void destroyWindowCb(GtkWidget* widget, GtkWidget* window)
{
gtk_main_quit();
}
static gboolean closeWebViewCb(WebKitWebView* webView, GtkWidget* window)
{
gtk_widget_destroy(window);
return TRUE;
}
如果这是您的尝试..发生的事情是,当您设置 GDK_KEY_PRESS_MASK 时,它也会反映在 webkit 上。
所以如果你评论“g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler) , 无效的);”
该程序应该可以正常工作
return主窗口处理程序为 true 将停止传播到 webview,returning false 将允许传播。
我有一个简单的 GTK 程序,在 window 中包含一个 webkit2 小部件,仅此而已。我希望能够过滤进入 webkit2 小部件的按键。起初我向 webkit 小部件添加了一个键掩码并添加了一个回调函数,但是在回调函数中传播事件后它只是递归地调用自身导致崩溃。为了解决这个问题,我将我的键掩码附加到 main-window,它是我的 webkit 小部件的父级,但这不再阻止输入停止,有时键释放事件会递归地相互调用。我想知道如何实现我的目标? (我使用了 GTK+ 输入事件处理文档页面中提到的所有不同类型的传播。)
当前密钥掩码:
gtk_widget_add_events(GTK_WIDGET(main_window), GDK_KEY_PRESS_MASK);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_release_event", G_CALLBACK(keypressHandeler), NULL);
当前回调函数(return 只是为了查看此时传播是否有效)
gboolean keypressHandeler(GtkWidget *widget, GdkEventKey *event, gpointer data){
if(event->type == GDK_KEY_PRESS)
printf("Key press\n");
if(event->type == GDK_KEY_RELEASE)
printf("Key release\n");
return gtk_widget_event(GTK_WIDGET(webView), event);
}
你的代码中的问题是你手动模拟信号通过 gtk_widget_event() (https://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-event)
因此在第一次调用 keypressHandeler 后 gtk_widget_event 将再次模拟相同的事件,因此它将 运行 进入无限循环。
如果您 return 在 "keypressHandeler" 中为 false 或 true,您的代码将有效
#include <gtk/gtk.h>
#include <webkit2/webkit2.h>
WebKitWebView *webView;
gboolean keypressHandeler(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
if (event->type == GDK_KEY_PRESS)
printf("Key press from mainwindow\n");
if (event->type == GDK_KEY_RELEASE)
printf("Key release\n");
//for the key use want to propogate
if (dont wanna propogate )
{
return TRUE;
} else {
return FALSE;
}
}
gboolean keypressHandeler2(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
if (event->type == GDK_KEY_PRESS)
printf("Key press from webkit\n");
if (event->type == GDK_KEY_RELEASE)
printf("Key release\n");
// set it as TRUE to stop porpogation.. (for some reason it propogating to mainwindow once)
return TRUE;
}
static void destroyWindowCb(GtkWidget* widget, GtkWidget* window);
static gboolean closeWebViewCb(WebKitWebView* webView, GtkWidget* window);
int main(int argc, char* argv[])
{
// Initialize GTK+
gtk_init(&argc, &argv);
// Create an 800x600 window that will contain the browser instance
GtkWidget *main_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size(GTK_WINDOW(main_window), 800, 600);
// Create a browser instance
webView = WEBKIT_WEB_VIEW(webkit_web_view_new());
// Put the browser area into the main window
gtk_container_add(GTK_CONTAINER(main_window), GTK_WIDGET(webView));
// Set up callbacks so that if either the main window or the browser instance is
// closed, the program will exit
gtk_widget_add_events(GTK_WIDGET(main_window), GDK_KEY_PRESS_MASK);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(webView)), "key_press_event", G_CALLBACK(keypressHandeler2), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_release_event", G_CALLBACK(keypressHandeler), NULL);
g_signal_connect(G_OBJECT(GTK_WIDGET(webView)), "key_release_event", G_CALLBACK(keypressHandeler2), NULL);
g_signal_connect(main_window, "destroy", G_CALLBACK(destroyWindowCb), NULL);
g_signal_connect(webView, "close", G_CALLBACK(closeWebViewCb), main_window);
// Load a web page into the browser instance
webkit_web_view_load_uri(webView, "http://www.webkitgtk.org/");
// Make sure that when the browser area becomes visible, it will get mouse
// and keyboard events
gtk_widget_grab_focus(GTK_WIDGET(webView));
// Make sure the main window and all its contents are visible
gtk_widget_show_all(main_window);
// Run the main GTK+ event loop
gtk_main();
return 0;
}
static void destroyWindowCb(GtkWidget* widget, GtkWidget* window)
{
gtk_main_quit();
}
static gboolean closeWebViewCb(WebKitWebView* webView, GtkWidget* window)
{
gtk_widget_destroy(window);
return TRUE;
}
如果这是您的尝试..发生的事情是,当您设置 GDK_KEY_PRESS_MASK 时,它也会反映在 webkit 上。
所以如果你评论“g_signal_connect(G_OBJECT(GTK_WIDGET(main_window)), "key_press_event", G_CALLBACK(keypressHandeler) , 无效的);” 该程序应该可以正常工作
return主窗口处理程序为 true 将停止传播到 webview,returning false 将允许传播。