node/Tasks: add 'clear filter' button

that does two things,

show the user that some filters are active (even if filters are collapsed),
and let the user to reset the filters all at once

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/node/Tasks.js

@@ -89,6 +89,13 @@ Ext.define('Proxmox.node.Tasks', {
 	    let vm = me.getViewModel();
 	    vm.set('showFilter', pressed);
 	},
+
+	clearFilter: function() {
+	    let me = this;
+	    me.lookup('filtertoolbar').query('field').forEach((field) => {
+		field.setValue(undefined);
+	    });
+	},
     },
 
     listeners: {
@@ -140,6 +147,44 @@ Ext.define('Proxmox.node.Tasks', {
 
 		return params;
 	    },
+	    filterCount: function(get) {
+		let count = 0;
+		if (get('typefilter')) {
+		    count++;
+		}
+		let status = get('statusfilter');
+		if ((Ext.isArray(status) && status.length > 0) ||
+		    (!Ext.isArray(status) && status)) {
+		    count++;
+		}
+		if (get('since')) {
+		    count++;
+		}
+		if (get('until')) {
+		    count++;
+		}
+
+		if (get('extraFilter')) {
+		    let extraFilter = get('extraFilter');
+		    for (const value of Object.values(extraFilter)) {
+			if (value !== undefined && value !== null && value !== "") {
+			    count++;
+			}
+		    }
+		}
+
+		return count;
+	    },
+	    clearFilterText: function(get) {
+		let count = get('filterCount');
+		let fieldMsg = '';
+		if (count > 1) {
+		    fieldMsg = ` (${count} ${gettext('Fields')})`;
+		} else if (count > 0) {
+		    fieldMsg = ` (1 ${gettext('Field')})`;
+		}
+		return gettext('Clear Filter') + fieldMsg;
+	    },
 	},
 
 	stores: {
@@ -186,6 +231,16 @@ Ext.define('Proxmox.node.Tasks', {
 		    handler: 'reload',
 		},
 		'->',
+		{
+		    xtype: 'button',
+		    bind: {
+			text: '{clearFilterText}',
+			disabled: '{!filterCount}',
+		    },
+		    text: gettext('Clear Filter'),
+		    enabled: false,
+		    handler: 'clearFilter',
+		},
 		{
 		    xtype: 'button',
 		    enableToggle: true,