--- /dev/null
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Components project.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+** * Redistributions of source code must retain the above copyright
+** notice, this list of conditions and the following disclaimer.
+** * Redistributions in binary form must reproduce the above copyright
+** notice, this list of conditions and the following disclaimer in
+** the documentation and/or other materials provided with the
+** distribution.
+** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
+** the names of its contributors may be used to endorse or promote
+** products derived from this software without specific prior written
+** permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// This file contains the implementation of CheckableGroup.qml functionality,
+// and CheckableGroup root element is identified by 'root'.
+
+var items = [];
+var selectedItem = null;
+var completed = false;
+
+
+function add(item) {
+ // Add the item, and if it's the case, check it as well.
+ items.push(item);
+ if (item.checked) {
+ check(item);
+ } else if (items.length == 1 && completed) {
+ // If we are already completed, this enforces the invariant of
+ // having always one item checked in the group. For exception
+ // case see onCompleted() function.
+ check(item);
+ }
+
+ // Connect so we know when items left the group or are requesting
+ // a different state (check or uncheck). Note that we register
+ // passing the item to be the 'this' value when the function
+ // is called.
+ item.exclusiveGroupChanged.connect(item, onItemExclusiveGroupChange);
+ item.checkedChanged.connect(item, onItemCheckedChange);
+}
+
+function onItemExclusiveGroupChange() {
+ var item = this;
+ if (item.checkGroup !== root) {
+ remove(item);
+ }
+}
+
+function onItemCheckedChange() {
+ var item = this;
+
+ // In those two cases we know the change was caused by the group, so we can ignore it.
+ if ((item === selectedItem && item.checked) ||
+ (item !== selectedItem && !item.checked)) {
+ return;
+ }
+
+ if (item.checked) {
+ // A non-selected item was checked, so we do the real check.
+ check(item);
+ } else if (items.length == 1) {
+ // Only one item, and it was unchecked. We have to rollback
+ // because it would break the group invariant.
+ //
+ // NOTE: This cause a glitch in the item.checked variable that
+ // goes false then true, however the CheckableGroup.selectedValue
+ // remains unchanged. We could avoid this with a custom setter
+ // in the 'checked' property of an item.
+ item.checked = true;
+ } else {
+ // The selected item was unchecked, choose another one to check.
+ var idx = (items.indexOf(item) + 1) % items.length
+ check(items[idx]);
+ }
+}
+
+function remove(item) {
+ // Remove the item from the list
+ var idx = items.indexOf(item);
+ if (idx == -1) {
+ console.log("Error: removing an invalid item.");
+ return;
+ }
+ items.splice(idx, 1);
+
+ item.exclusiveGroupChanged.disconnect(item, onItemExclusiveGroupChange);
+ item.checkedChanged.disconnect(item, onItemCheckedChange);
+
+ // If we are removing the selected item, we need to find a
+ // replacement to be selected...
+ if (selectedItem === item) {
+ selectedItem = null;
+ if (items.length > 0) {
+ var otherIdx = idx % items.length;
+ check(items[otherIdx]);
+ } else {
+ // ...or simply having no selectedValue.
+ root.selectedValue = null;
+ }
+ }
+}
+
+/// Select one item, setting the selectedValue in the group
+function check(item) {
+ // It is important to have the right item in the 'selectedItem'
+ // before the changes since we use that to identify that the change
+ // was made by us.
+ var oldSelectedItem = selectedItem
+ selectedItem = item;
+ if (oldSelectedItem)
+ oldSelectedItem.checked = false;
+ item.checked = true;
+ root.selectedValue = item.value;
+}
+
+function onCompleted() {
+ completed = true;
+
+ // When the QML file is loaded, and no items on it had 'checkable: true' (which
+ // would be considered in the add() function), then we simply select one of them
+ // to enforce the rule of having one item selected.
+ //
+ // The delayed selection is useful because it allow to declare in the QML file
+ // one item as 'checked' and don't see a "glitch" in the selectedValue because
+ // another item was added before to the group (and could be selected if this was
+ // not delayed).
+ if (!selectedItem && items.length > 0) {
+ check(items[0]);
+ }
+}
+
+function clear() {
+ var itemsLength = items.length;
+ for (var i = 0; i < itemsLength; i++) {
+ var item = items[i];
+ item.exclusiveGroupChanged.disconnect(item, onItemExclusiveGroupChange);
+ item.checkedChanged.disconnect(item, onItemCheckedChange);
+ item.exclusiveGroup = null;
+ }
+
+ items = [];
+ selectedItem = null;
+ root.selectedValue = null;
+}
projects / mardrone / blobdiff