Add a way to set the default render type of text-like elements

f3446071da8357620d0c8593a04e3b4fbba88f21 introduced a build-time
way to select the default render type of text-like elements.
This patch adds also a way to select it at runtime, via a setter
on QQuickWindow. (QQuickWindow has been chosen as convenience,
rather than adding another namespace/class to just have this
setter.)

Given that QT_QUICK_DEFAULT_TEXT_RENDER_TYPE was never documented,
I've taken the liberty of changing the accepted values for it
(to match the new enumerator names in QQuickWindow, rather than
the ones in QQuickText/QQuickTextEdit/etc.).

[ChangeLog][QtQuick][QQuickWindow] It is now possible to set the
default render type of text-like elements globally via the
QQuickWindow::setTextRenderType() function. If you were using
the (undocumented) QT_QUICK_DEFAULT_TEXT_RENDER_TYPE macro
when building Qt Quick for the same purpose, note that the
macro value needs now to be set to the "NativeTextRendering"
value, instead of "NativeRendering".

Change-Id: Id4b2dc3ec823971486e445ca4173b8be848fb4e3
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

9 files changed, 91 insertions, 20 deletions

diff --git a/src/quick/items/qquicktext.cpp b/src/quick/items/qquicktext.cpp
index 5ca0bb5f79..07cc1ff76e 100644
--- a/src/quick/items/qquicktext.cpp
+++ b/src/quick/items/qquicktext.cpp
@@ -80,11 +80,7 @@ QQuickTextPrivate::QQuickTextPrivate()
     , elideMode(QQuickText::ElideNone), hAlign(QQuickText::AlignLeft), vAlign(QQuickText::AlignTop)
     , format(QQuickText::AutoText), wrapMode(QQuickText::NoWrap)
     , style(QQuickText::Normal)
-#if defined(QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-    , renderType(QQuickText::QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-#else
-    , renderType(QQuickText::QtRendering)
-#endif
+    , renderType(QQuickTextUtil::textRenderType<QQuickText>())
     , updateType(UpdatePaintNode)
     , maximumLineCountValid(false), updateOnComponentComplete(true), richText(false)
     , styledText(false), widthExceeded(false), heightExceeded(false), internalWidthUpdate(false)
@@ -2827,7 +2823,7 @@ void QQuickText::hoverLeaveEvent(QHoverEvent *event)
 
     Supported render types are:
     \list
-    \li Text.QtRendering - the default
+    \li Text.QtRendering
     \li Text.NativeRendering
     \endlist
 
@@ -2835,6 +2831,8 @@ void QQuickText::hoverLeaveEvent(QHoverEvent *event)
     not require advanced features such as transformation of the text. Using such features in
     combination with the NativeRendering render type will lend poor and sometimes pixelated
     results.
+
+    The default rendering type is determined by \l QQuickWindow::textRenderType().
 */
 QQuickText::RenderType QQuickText::renderType() const
 {
diff --git a/src/quick/items/qquicktextedit.cpp b/src/quick/items/qquicktextedit.cpp
index f22c5f00be..193f804c13 100644
--- a/src/quick/items/qquicktextedit.cpp
+++ b/src/quick/items/qquicktextedit.cpp
@@ -45,7 +45,6 @@
 #include "qquickwindow.h"
 #include "qquicktextnode_p.h"
 #include "qquicktextnodeengine_p.h"
-#include "qquicktextutil_p.h"
 
 #include <QtCore/qmath.h>
 #include <QtGui/qguiapplication.h>
@@ -495,7 +494,7 @@ void QQuickTextEdit::setTextFormat(TextFormat format)
 
     Supported render types are:
     \list
-    \li Text.QtRendering - the default
+    \li Text.QtRendering
     \li Text.NativeRendering
     \endlist
 
@@ -503,6 +502,8 @@ void QQuickTextEdit::setTextFormat(TextFormat format)
     not require advanced features such as transformation of the text. Using such features in
     combination with the NativeRendering render type will lend poor and sometimes pixelated
     results.
+
+    The default rendering type is determined by \l QQuickWindow::textRenderType().
 */
 QQuickTextEdit::RenderType QQuickTextEdit::renderType() const
 {
diff --git a/src/quick/items/qquicktextedit_p_p.h b/src/quick/items/qquicktextedit_p_p.h
index 03bce00cb0..455fffbcbc 100644
--- a/src/quick/items/qquicktextedit_p_p.h
+++ b/src/quick/items/qquicktextedit_p_p.h
@@ -53,6 +53,7 @@
 
 #include "qquicktextedit_p.h"
 #include "qquickimplicitsizeitem_p_p.h"
+#include "qquicktextutil_p.h"
 
 #include <QtQml/qqml.h>
 #include <QtCore/qlist.h>
@@ -112,11 +113,7 @@ public:
         , quickDocument(0), lastSelectionStart(0), lastSelectionEnd(0), lineCount(0)
         , hAlign(QQuickTextEdit::AlignLeft), vAlign(QQuickTextEdit::AlignTop)
         , format(QQuickTextEdit::PlainText), wrapMode(QQuickTextEdit::NoWrap)
-#if defined(QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-        , renderType(QQuickTextEdit::QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-#else
-        , renderType(QQuickTextEdit::QtRendering)
-#endif
+        , renderType(QQuickTextUtil::textRenderType<QQuickTextEdit>())
         , contentDirection(Qt::LayoutDirectionAuto)
         , mouseSelectionMode(QQuickTextEdit::SelectCharacters)
 #if QT_CONFIG(im)
diff --git a/src/quick/items/qquicktextinput.cpp b/src/quick/items/qquicktextinput.cpp
index 06ad0a9dbf..d01d604171 100644
--- a/src/quick/items/qquicktextinput.cpp
+++ b/src/quick/items/qquicktextinput.cpp
@@ -40,7 +40,6 @@
 #include "qquicktextinput_p.h"
 #include "qquicktextinput_p_p.h"
 #include "qquickwindow.h"
-#include "qquicktextutil_p.h"
 
 #include <private/qqmlglobal_p.h>
 #include <private/qv4scopedvalue_p.h>
@@ -157,7 +156,7 @@ void QQuickTextInput::setText(const QString &s)
 
     Supported render types are:
     \list
-    \li Text.QtRendering - the default
+    \li Text.QtRendering
     \li Text.NativeRendering
     \endlist
 
@@ -165,6 +164,8 @@ void QQuickTextInput::setText(const QString &s)
     not require advanced features such as transformation of the text. Using such features in
     combination with the NativeRendering render type will lend poor and sometimes pixelated
     results.
+
+    The default rendering type is determined by \l QQuickWindow::textRenderType().
 */
 QQuickTextInput::RenderType QQuickTextInput::renderType() const
 {
diff --git a/src/quick/items/qquicktextinput_p_p.h b/src/quick/items/qquicktextinput_p_p.h
index 0bf5779a53..c3218197a4 100644
--- a/src/quick/items/qquicktextinput_p_p.h
+++ b/src/quick/items/qquicktextinput_p_p.h
@@ -43,6 +43,7 @@
 #include "qquicktextinput_p.h"
 #include "qquicktext_p.h"
 #include "qquickimplicitsizeitem_p_p.h"
+#include "qquicktextutil_p.h"
 
 #include <QtQml/qqml.h>
 #include <QtCore/qelapsedtimer.h>
@@ -122,11 +123,7 @@ public:
         , vAlign(QQuickTextInput::AlignTop)
         , wrapMode(QQuickTextInput::NoWrap)
         , m_echoMode(QQuickTextInput::Normal)
-#if defined(QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-        , renderType(QQuickTextInput::QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
-#else
-        , renderType(QQuickTextInput::QtRendering)
-#endif
+        , renderType(QQuickTextUtil::textRenderType<QQuickTextInput>())
         , updateType(UpdatePaintNode)
         , mouseSelectionMode(QQuickTextInput::SelectCharacters)
         , m_layoutDirection(Qt::LayoutDirectionAuto)
diff --git a/src/quick/items/qquicktextutil_p.h b/src/quick/items/qquicktextutil_p.h
index 01055c95ec..bad5e738a8 100644
--- a/src/quick/items/qquicktextutil_p.h
+++ b/src/quick/items/qquicktextutil_p.h
@@ -54,6 +54,7 @@
 #include <QtQml/qqml.h>
 #include <QtQml/qqmlincubator.h>
 #include <QtQuick/qquickitem.h>
+#include <QtQuick/qquickwindow.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -64,6 +65,7 @@ public:
     template <typename Private> static void setCursorDelegate(Private *d, QQmlComponent *delegate);
     template <typename Private> static void createCursor(Private *d);
 
+    template <typename T> static typename T::RenderType textRenderType();
 
     static qreal alignedX(qreal textWidth, qreal itemWidth, int alignment);
     static qreal alignedY(qreal textHeight, qreal itemHeight, int alignment);
@@ -124,6 +126,20 @@ void QQuickTextUtil::createCursor(Private *d)
     parent->update();
 }
 
+template <typename T>
+typename T::RenderType QQuickTextUtil::textRenderType()
+{
+    switch (QQuickWindow::textRenderType()) {
+    case QQuickWindow::QtTextRendering:
+        return T::QtRendering;
+    case QQuickWindow::NativeTextRendering:
+        return T::NativeRendering;
+    }
+
+    Q_UNREACHABLE();
+    return T::QtRendering;
+}
+
 QT_END_NAMESPACE
 
 #endif
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 7b331251f0..bc99f49667 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -93,6 +93,12 @@ extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_
 
 bool QQuickWindowPrivate::defaultAlphaBuffer = false;
 
+#if defined(QT_QUICK_DEFAULT_TEXT_RENDER_TYPE)
+QQuickWindow::TextRenderType QQuickWindowPrivate::textRenderType = QQuickWindow::QT_QUICK_DEFAULT_TEXT_RENDER_TYPE;
+#else
+QQuickWindow::TextRenderType QQuickWindowPrivate::textRenderType = QQuickWindow::QtTextRendering;
+#endif
+
 void QQuickWindowPrivate::updateFocusItemTransform()
 {
 #if QT_CONFIG(im)
@@ -3825,6 +3831,23 @@ QQmlIncubationController *QQuickWindow::incubationController() const
  */
 
 /*!
+    \enum QQuickWindow::TextRenderType
+    \since 5.10
+
+    This enum describes the default render type of text-like elements in Qt
+    Quick (\l Text, \l TextInput, etc.).
+
+    Select NativeTextRendering if you prefer text to look native on the target
+    platform and do not require advanced features such as transformation of the
+    text. Using such features in combination with the NativeTextRendering
+    render type will lend poor and sometimes pixelated results.
+
+    \value QtTextRendering Use Qt's own rasterization algorithm.
+
+    \value NativeTextRendering Use the operating system's native rasterizer for text.
+*/
+
+/*!
     \fn void QQuickWindow::beforeSynchronizing()
 
     This signal is emitted before the scene graph is synchronized with the QML state.
@@ -4846,6 +4869,34 @@ QSGNinePatchNode *QQuickWindow::createNinePatchNode() const
     return isSceneGraphInitialized() ? d->context->sceneGraphContext()->createNinePatchNode() : nullptr;
 }
 
+/*!
+    \since 5.10
+
+    Returns the render type of text-like elements in Qt Quick.
+    The default is QQuickWindow::QtTextRendering.
+
+    \sa setTextRenderType()
+*/
+QQuickWindow::TextRenderType QQuickWindow::textRenderType()
+{
+    return QQuickWindowPrivate::textRenderType;
+}
+
+/*!
+    \since 5.10
+
+    Sets the default render type of text-like elements in Qt Quick to \a renderType.
+
+    \note setting the render type will only affect elements created afterwards;
+    the render type of existing elements will not be modified.
+
+    \sa textRenderType()
+*/
+void QQuickWindow::setTextRenderType(QQuickWindow::TextRenderType renderType)
+{
+    QQuickWindowPrivate::textRenderType = renderType;
+}
+
 #include "moc_qquickwindow.cpp"
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickwindow.h b/src/quick/items/qquickwindow.h
index d1a16fbeb6..022c4738f2 100644
--- a/src/quick/items/qquickwindow.h
+++ b/src/quick/items/qquickwindow.h
@@ -100,6 +100,12 @@ public:
     };
     Q_ENUM(SceneGraphError)
 
+    enum TextRenderType {
+        QtTextRendering,
+        NativeTextRendering
+    };
+    Q_ENUM(TextRenderType)
+
     explicit QQuickWindow(QWindow *parent = Q_NULLPTR);
     explicit QQuickWindow(QQuickRenderControl *renderControl);
 
@@ -170,6 +176,9 @@ public:
     QSGImageNode *createImageNode() const;
     QSGNinePatchNode *createNinePatchNode() const;
 
+    static TextRenderType textRenderType();
+    static void setTextRenderType(TextRenderType renderType);
+
 Q_SIGNALS:
     void frameSwapped();
     Q_REVISION(2) void openglContextCreated(QOpenGLContext *context);
diff --git a/src/quick/items/qquickwindow_p.h b/src/quick/items/qquickwindow_p.h
index 14564a7f55..837ef11d25 100644
--- a/src/quick/items/qquickwindow_p.h
+++ b/src/quick/items/qquickwindow_p.h
@@ -279,6 +279,7 @@ public:
     mutable QQuickWindowIncubationController *incubationController;
 
     static bool defaultAlphaBuffer;
+    static QQuickWindow::TextRenderType textRenderType;
 
     static bool dragOverThreshold(qreal d, Qt::Axis axis, QMouseEvent *event, int startDragThreshold = -1);