Support HTML5 form validation feature

HTML5 provides built-in form validation that is supported by chromium.
The form validation messages should be shown by the browser therefore
new MessageBubble UI element has been added to Quick and Widget
implementations.
This patch implements chromium's form validation events and shows the
messages in a MessageBubble.

Change-Id: I0c8f4f102823117e2bfb16ff8a4c503635491939
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>

2 files changed, 150 insertions, 1 deletions

diff --git a/src/webengine/ui/MessageBubble.qml b/src/webengine/ui/MessageBubble.qml
new file mode 100644
index 000000000..4328eae40
--- /dev/null
+++ b/src/webengine/ui/MessageBubble.qml
@@ -0,0 +1,147 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.1
+
+Item {
+    id: bubble
+
+    width: 1
+    height: 1
+
+    property int maxWidth: 0
+    property string mainText: "";
+    property string subText: "";
+
+    property int border: 1
+
+    property int arrowWidth: 18
+    property int arrowHeight: 18
+    property int arrowOffset: 18
+
+    property int marginLeft: border + 8
+    property int marginTop: border + arrowHeight + 6
+    property int marginRight: border + 8
+    property int marginBottom: border + 6
+
+    Column {
+        id: messageColumn
+
+        x: bubble.marginLeft
+        y: bubble.marginTop
+        z: 1
+
+        spacing: 5
+
+        Text {
+            id: message
+            width: bubble.maxWidth
+
+            wrapMode: Text.WordWrap
+            elide: Text.ElideNone
+            clip: true
+
+            font.pointSize: subMessage.font.pointSize + 4
+
+            text: bubble.mainText
+        }
+
+        Text {
+            id: subMessage
+            width: bubble.maxWidth
+
+            wrapMode: Text.WordWrap
+            elide: Text.ElideNone
+            clip: true
+
+            text: bubble.subText
+        }
+    }
+
+    Canvas {
+        id: bubbleCanvas
+
+        property int textWidth: Math.min(bubble.maxWidth, Math.max(message.paintedWidth, subMessage.paintedWidth))
+        property int textHeight: message.paintedHeight + (subMessage.paintedWidth > 0 ? (messageColumn.spacing + subMessage.paintedHeight) : 0)
+
+        width: textWidth + bubble.marginLeft + bubble.marginRight
+        height: textHeight + bubble.marginTop + bubble.marginBottom
+
+        property int cornerRadius: 7
+
+        property int messageBoxLeft: 0
+        property int messageBoxTop: bubble.arrowHeight
+        property int messageBoxRight: width - border
+        property int messageBoxBottom: height - border
+
+        onPaint: {
+            var ctx = getContext("2d")
+
+            ctx.lineWidth = bubble.border
+            ctx.strokeStyle = "#555"
+            ctx.fillStyle = "#ffffe1"
+
+            ctx.beginPath()
+
+            ctx.moveTo(messageBoxLeft + cornerRadius, messageBoxTop)
+
+            // Arrow
+            ctx.lineTo(messageBoxLeft + bubble.arrowOffset, messageBoxTop)
+            ctx.lineTo(messageBoxLeft + bubble.arrowOffset, messageBoxTop - bubble.arrowHeight)
+            ctx.lineTo(messageBoxLeft + bubble.arrowOffset + bubble.arrowWidth, messageBoxTop)
+
+            // Message Box
+            ctx.lineTo(messageBoxRight - cornerRadius, messageBoxTop)
+            ctx.quadraticCurveTo(messageBoxRight, messageBoxTop, messageBoxRight, messageBoxTop + cornerRadius)
+            ctx.lineTo(messageBoxRight, messageBoxBottom - cornerRadius)
+            ctx.quadraticCurveTo(messageBoxRight, messageBoxBottom, messageBoxRight - cornerRadius, messageBoxBottom)
+            ctx.lineTo(messageBoxLeft + cornerRadius, messageBoxBottom)
+            ctx.quadraticCurveTo(messageBoxLeft, messageBoxBottom, messageBoxLeft, messageBoxBottom - cornerRadius)
+            ctx.lineTo(messageBoxLeft, messageBoxTop + cornerRadius)
+            ctx.quadraticCurveTo(messageBoxLeft, messageBoxTop, messageBoxLeft + cornerRadius, messageBoxTop)
+
+            ctx.closePath()
+
+            ctx.fill()
+            ctx.stroke()
+        }
+
+        onPainted: {
+            bubble.width = bubbleCanvas.width
+            bubble.height = bubbleCanvas.height
+        }
+    }
+}
diff --git a/src/webengine/ui/ui.pro b/src/webengine/ui/ui.pro
index a5ae648cb..fdf7a85bc 100644
--- a/src/webengine/ui/ui.pro
+++ b/src/webengine/ui/ui.pro
@@ -9,6 +9,8 @@ QML_FILES += \
     # Menus. Based on Qt Quick Controls
     Menu.qml \
     MenuItem.qml \
-    MenuSeparator.qml
+    MenuSeparator.qml \
+    # Message Bubble
+    MessageBubble.qml
 
 load(qml_module)