Document DropShadow and Glow's transparentBorder properties.

Change-Id: I1f4be68c5b364e5d2151ed26b079a0f00ac31f0c
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

6 files changed, 207 insertions, 0 deletions

diff --git a/src/effects/DropShadow.qml b/src/effects/DropShadow.qml
index b73e244..909fef9 100644
--- a/src/effects/DropShadow.qml
+++ b/src/effects/DropShadow.qml
@@ -354,6 +354,22 @@ Item {
     */
     property bool cached: false
 
+    /*!
+        This property determines whether or not the effect has a transparent
+        border.
+
+        When set to \c true, the exterior of the item is padded with a 1 pixel
+        wide transparent edge, making sampling outside the source texture use
+        transparency instead of the edge pixels. Without this property, an
+        image which has opaque edges will not get a blurred edge.
+
+        In the image below, the Rectangle on the left has transparent borders
+        and has blurred edges, whereas the Rectangle on the right does not:
+
+        \snippet DropShadow-transparentBorder-example.qml example
+
+        \image transparentBorder.png
+    */
     property bool transparentBorder: false
 
     Loader {
diff --git a/src/effects/Glow.qml b/src/effects/Glow.qml
index c5a82c6..668fb74 100644
--- a/src/effects/Glow.qml
+++ b/src/effects/Glow.qml
@@ -261,6 +261,23 @@ Item {
 
     */
     property bool cached: false
+
+    /*!
+        This property determines whether or not the effect has a transparent
+        border.
+
+        When set to \c true, the exterior of the item is padded with a 1 pixel
+        wide transparent edge, making sampling outside the source texture use
+        transparency instead of the edge pixels. Without this property, an
+        image which has opaque edges will not get a blurred edge.
+
+        In the snippet below, the Rectangle on the left has transparent borders
+        and has blurred edges, whereas the Rectangle on the right does not.
+
+        \snippet Glow-transparentBorder-example.qml example
+
+        \image transparentBorder.png
+    */
     property bool transparentBorder: false
 
     Loader {
diff --git a/src/effects/doc/images/DropShadow-transparentBorder.png b/src/effects/doc/images/DropShadow-transparentBorder.png
new file mode 100644
index 0000000..bfdaebc
--- /dev/null
+++ b/src/effects/doc/images/DropShadow-transparentBorder.png
diff --git a/src/effects/doc/images/Glow-transparentBorder.png b/src/effects/doc/images/Glow-transparentBorder.png
new file mode 100644
index 0000000..b26aad3
--- /dev/null
+++ b/src/effects/doc/images/Glow-transparentBorder.png
diff --git a/src/effects/doc/snippets/DropShadow-transparentBorder-example.qml b/src/effects/doc/snippets/DropShadow-transparentBorder-example.qml
new file mode 100644
index 0000000..4f7d6f6
--- /dev/null
+++ b/src/effects/doc/snippets/DropShadow-transparentBorder-example.qml
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Graphical Effects module.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 Digia Plc 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [example]
+import QtQuick 2.0
+import QtGraphicalEffects 1.0
+
+Rectangle {
+    width: 180
+    height: 100
+
+    Row {
+        anchors.centerIn: parent
+        spacing: 16
+
+        Rectangle {
+            id: normalRect
+            width: 60
+            height: 60
+            color: "#444"
+
+            layer.enabled: true
+
+            layer.effect: DropShadow {
+                radius: 4
+                samples: radius * 2
+                source: normalRect
+                color: Qt.rgba(0, 0, 0, 0.5)
+            }
+        }
+
+        Rectangle {
+            id: transparentBorderRect
+            width: 60
+            height: 60
+            color: "#444"
+
+            layer.enabled: true
+
+            layer.effect: DropShadow {
+                radius: 4
+                samples: radius * 2
+                source: transparentBorderRect
+                color: Qt.rgba(0, 0, 0, 0.5)
+                transparentBorder: true
+            }
+        }
+    }
+}
+//! [example]
diff --git a/src/effects/doc/snippets/Glow-transparentBorder-example.qml b/src/effects/doc/snippets/Glow-transparentBorder-example.qml
new file mode 100644
index 0000000..ad04977
--- /dev/null
+++ b/src/effects/doc/snippets/Glow-transparentBorder-example.qml
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Graphical Effects module.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 Digia Plc 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [example]
+import QtQuick 2.0
+import QtGraphicalEffects 1.0
+
+Rectangle {
+    width: 180
+    height: 100
+
+    Row {
+        anchors.centerIn: parent
+        spacing: 16
+
+        Rectangle {
+            id: normalRect
+            width: 60
+            height: 60
+            color: "#444"
+
+            layer.enabled: true
+
+            layer.effect: Glow {
+                radius: 4
+                samples: radius * 2
+                source: normalRect
+                color: "steelblue"
+            }
+        }
+
+        Rectangle {
+            id: transparentBorderRect
+            width: 60
+            height: 60
+            color: "#444"
+
+            layer.enabled: true
+
+            layer.effect: Glow {
+                radius: 4
+                samples: radius * 2
+                source: transparentBorderRect
+                color: "steelblue"
+                transparentBorder: true
+            }
+        }
+    }
+}
+//! [example]