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POCannot connect a button click to a C function using GTK WebKit Webview
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  1. POCannot connect a button click to a C function using GTK WebKit Webview
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    copied!<p>I am creating an application where the GUI is presented using HTML and JavaScript and the button actions need to interact with hardware attached via USB. I have all the hardware related functions as a shared library (.so) files.<br> OS: Ubuntu Server 12.04<br> IDE: Eclipse Juno<br> Language: C, JavaScript<br> Libraries: GTK, Webkit Webview </p> <p>I am using DOM node traversal to iterate through the controls in the HTML page. I am able to get the buttons using values, but am unable to successfully add events to the button clicks. The HTML page and the corresponding GTK C code are as below.</p> <pre><code>&lt;html&gt; &lt;head&gt; &lt;script type="text/javascript"&gt; function read() { alert( 'Read called' ); } function configure() { alert( 'configure called' ); } &lt;/script&gt; &lt;h1&gt; &lt;font color="white"&gt; GTK WebKit &lt;/font&gt; &lt;/h1&gt; &lt;/head&gt; &lt;body&gt; &lt;label id="labelStep1"&gt; &lt;font color="white" size="4"&gt; Step 1: &lt;/font&gt; &lt;/label&gt; &lt;input type="button" onclick="configure()" value="Configure"&gt; &lt;/br&gt; &lt;label id="labelStep2"&gt; &lt;font color="white" size="4"&gt; Step 2: &lt;/font&gt; &lt;/label&gt; &lt;input type="button" onclick="read()" value="Read"&gt; &lt;font color="white" size="6"&gt; &lt;/font&gt; &lt;/input&gt; &lt;/br&gt; &lt;/br&gt; &lt;/body&gt; &lt;/html&gt; </code></pre> <p>GTK.c:</p> <pre><code>#include &lt;gtk/gtk.h&gt; #include &lt;webkit/webkit.h&gt; #include &lt;webkit/webkitwebview.h&gt; static void destroyWindow(GtkWidget *pWidget1, GtkWidget *pWidget2); static gboolean closeWebViewCB(WebKitWebView *pWebView, GtkWidget *pWindow); static void loadStatusCB(WebKitWebView *pWebView, GParamSpec *pSpec, void *pContext); int main (int argc, char *argv[]) { GtkWidget *window; GtkWidget *label; gtk_init (&amp;argc, &amp;argv); /* create the main, top level, window */ window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_window_resize(window, 1024, 768); WebKitWebView *pWebView = WEBKIT_WEB_VIEW(webkit_web_view_new()); GtkWidget *pscrolledWnd = gtk_scrolled_window_new(NULL, NULL); gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(pscrolledWnd), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC); gtk_window_resize(pscrolledWnd, 1024, 768); gtk_container_add(GTK_CONTAINER(pscrolledWnd), GTK_WIDGET(pWebView)); gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(pscrolledWnd)); webkit_web_view_load_uri(pWebView, "file:///home/developer/Desktop/Dan/workspace/GTK+/Resources/WebViewGTK.html"); gtk_widget_grab_focus(GTK_WIDGET(pWebView)); /* give it the title */ gtk_window_set_title (GTK_WINDOW (window), "GTK WebKit"); /* Connect the destroy signal of the window to gtk_main_quit * When the window is about to be destroyed we get a notification and * stop the main GTK+ loop */ g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL); g_signal_connect(pWebView, "close-web-view", G_CALLBACK(closeWebViewCB), window); g_signal_connect(pWebView, "notify::load-status", G_CALLBACK(loadStatusCB), window); /* Create the "Hello, World" label */ label = gtk_label_new ("Hello, World"); /* and insert it into the main window */ gtk_container_add (GTK_CONTAINER (window), label); /* make sure that everything, window and label, are visible */ gtk_widget_show_all (window); /* start the main loop, and let it rest there until the application is closed */ gtk_main (); return 0; } static void destroyWindow(GtkWidget *pWidget1, GtkWidget *pWidget2) { gtk_main_quit(); } static gboolean closeWebViewCB(WebKitWebView *pWebView, GtkWidget *pWindow) { gtk_widget_destroy(pWindow); return 1; } static gboolean TestCB(WebKitWebView *pWebView, GtkWidget *pWindow) { GtkWidget *pMsgBox = gtk_message_dialog_new(pWindow, GTK_DIALOG_DESTROY_WITH_PARENT, GTK_MESSAGE_INFO, GTK_BUTTONS_YES_NO, "TestCB Called()!"); gtk_dialog_run(pMsgBox); gtk_widget_destroy(pMsgBox); return true; } static void handleWebPageLoadEvents(WebKitWebView *pWebView, void * pContext) { int nElemIndex = 0; char *pChElemName = NULL; char chMsgBoxText[255] = { 0 }; static int nEventAddCallCount = 0; GtkWidget *pMsgBox = NULL;//gtk_message_dialog_new(pContext, GTK_DIALOG_DESTROY_WITH_PARENT, GTK_MESSAGE_INFO, GTK_BUTTONS_CLOSE, chMsgBoxText /*"handleWebPageLoadEvents Called()!"*/); WebKitDOMDocument *pDoc = webkit_web_view_get_dom_document(pWebView); WebKitDOMNodeList *pDomNodeList = webkit_dom_document_get_elements_by_tag_name(pDoc, "*"); gulong elements_Count = webkit_dom_node_list_get_length(pDomNodeList); for(nElemIndex = 0; nElemIndex &lt; elements_Count; nElemIndex ++) { WebKitDOMNode *pElement = webkit_dom_node_list_item(pDomNodeList, nElemIndex); if(WEBKIT_DOM_IS_HTML_INPUT_ELEMENT(pElement)) { g_object_get(pElement, "value", &amp; pChElemName, NULL); if(NULL != pChElemName) { if(g_str_equal("Configure", pChElemName) ) { if(webkit_dom_event_target_add_event_listener(WEBKIT_DOM_EVENT_TARGET(pElement), pChElemName, G_CALLBACK(TestCB), false, pContext) ) sprintf(chMsgBoxText, "webkit_dom_event_target_add_event_listener --&gt; %s --&gt; OK", pChElemName); else sprintf(chMsgBoxText, "webkit_dom_event_target_add_event_listener --&gt; %s --&gt; FAILED", pChElemName); } if(g_str_equal("Read", pChElemName) ) { if( webkit_dom_event_target_add_event_listener(WEBKIT_DOM_EVENT_TARGET(pElement), /*pChElemName*/ "Read", G_CALLBACK(TestCB), false, pContext) ) sprintf(chMsgBoxText, "webkit_dom_event_target_add_event_listener --&gt; %s --&gt; OK", pChElemName); else sprintf(chMsgBoxText, "webkit_dom_event_target_add_event_listener --&gt; %s --&gt; FAILED", pChElemName); } pMsgBox = gtk_message_dialog_new(pContext, GTK_DIALOG_DESTROY_WITH_PARENT, GTK_MESSAGE_INFO, GTK_BUTTONS_CLOSE, chMsgBoxText); gtk_dialog_run(pMsgBox); gtk_widget_destroy(pMsgBox); if(pChElemName) g_free(pChElemName); } } } g_object_unref(pDomNodeList); } static void loadStatusCB(WebKitWebView *pWebView, GParamSpec *pSpec, void *pContext) { char Msg[64] = { 0 }; static unsigned int nCounter = 0; WebKitLoadStatus status = webkit_web_view_get_load_status(pWebView); //GObject *pObject = G_OBJECT(pWebView); g_object_freeze_notify(pContext); switch(status) { case WEBKIT_LOAD_FINISHED: sprintf(Msg, "WEBKIT_LOAD_FINISHED~%d", nCounter); handleWebPageLoadEvents(pWebView, pContext); break; case WEBKIT_LOAD_PROVISIONAL: sprintf(Msg, "WEBKIT_LOAD_PROVISIONAL~%d", nCounter); break; case WEBKIT_LOAD_COMMITTED: sprintf(Msg, "WEBKIT_LOAD_COMMITTED~%d", nCounter); break; case WEBKIT_LOAD_FIRST_VISUALLY_NON_EMPTY_LAYOUT: sprintf(Msg, "WEBKIT_LOAD_FIRST_VISUALLY_NON_EMPTY_LAYOUT~%d", nCounter); break; case WEBKIT_LOAD_FAILED: sprintf(Msg, "WEBKIT_LOAD_FAILED~%d", nCounter); break; default: sprintf(Msg, "default~%d", nCounter); break; } } </code></pre> <p>I am very new to GTK, so any help is appreciated.</p> <p>Regards.</p>
 

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