TL;DR;
有没有办法强制在网页的模态框内设置焦点?点击页面中的特定链接时,会出现一个模态框(类似于fancybox
或jQuery.ui.dialog
),包含链接和表单元素。如果用户使用"tab"
键,则可以将焦点放在页面上的每个元素上,包括模态框内部和外部的元素。如果可能的话,我想在CSS或JavaScript中强制将焦点保持在模态框内。
我知道这是可能的,因为jQuery.ui.dialog
可以使用modal
选项来实现,以下是一个示例http://jsfiddle.net/pomeh/QjLJk/1/show/。我试图查看源代码,但我没有确切地了解它的工作原理。以下是我找到的jQuery UI源代码中解决此问题的代码:
this.document.bind( "focusin.dialog", function( event ) {
if ( !that._allowInteraction( event ) ) {
event.preventDefault();
$(".ui-dialog:visible:last .ui-dialog-content")
.data( widgetFullName )._focusTabbable();
}
});
_allowInteraction: function( event ) {
if ( $( event.target ).closest(".ui-dialog").length ) {
return true;
}
// TODO: Remove hack when datepicker implements
// the .ui-front logic (#8989)
return !!$( event.target ).closest(".ui-datepicker").length;
},
_focusTabbable: function() {
// Set focus to the first match:
// 1. First element inside the dialog matching [autofocus]
// 2. Tabbable element inside the content element
// 3. Tabbable element inside the buttonpane
// 4. The close button
// 5. The dialog itself
var hasFocus = this.element.find("[autofocus]");
if ( !hasFocus.length ) {
hasFocus = this.element.find(":tabbable");
}
if ( !hasFocus.length ) {
hasFocus = this.uiDialogButtonPane.find(":tabbable");
}
if ( !hasFocus.length ) {
hasFocus = this.uiDialogTitlebarClose.filter(":tabbable");
}
if ( !hasFocus.length ) {
hasFocus = this.uiDialog;
}
hasFocus.eq( 0 ).focus();
}
keydown: function( event ) {
if ( this.options.closeOnEscape && !event.isDefaultPrevented() && event.keyCode &&
event.keyCode === $.ui.keyCode.ESCAPE ) {
event.preventDefault();
this.close( event );
return;
}
// prevent tabbing out of dialogs
if ( event.keyCode !== $.ui.keyCode.TAB ) {
return;
}
var tabbables = this.uiDialog.find(":tabbable"),
first = tabbables.filter(":first"),
last = tabbables.filter(":last");
if ( ( event.target === last[0] || event.target === this.uiDialog[0] ) && !event.shiftKey ) {
first.focus( 1 );
event.preventDefault();
} else if ( ( event.target === first[0] || event.target === this.uiDialog[0] ) && event.shiftKey ) {
last.focus( 1 );
event.preventDefault();
}
}