Add declarative QQuickTextMetrics API from QQuickFontMetrics invokables

This allows use of a declarative API for the functions in QFontMetricsF
which take parameters. This solves the problem of QML expressions that
use QML methods not being re-evaluated when the internal data changes,
by allowing the user to set the arguments as properties of a
TextMetrics object, that would otherwise have to be passed to QML
methods.

For example:

    FontMetrics {
        id: fontMetrics
    }

    property rect r: fontMetrics.boundingRect("Blah")

At some point, the font of the FontMetrics object is changed, but r
will still represent the original bounding rect. Instead, the user will
now write:

    TextMetrics {
        id: textMetrics
        text: "Blah"
    }

    property rect r: textMetrics.boundingRect

The QML methods remain in QQuickFontMetrics for those who need an
imperative API.

[ChangeLog][QtQuick] Added QQuickTextMetrics, which provides a
declarative API for the functions in QFontMetricsF which take
arguments.

Change-Id: I019dc4639531906fc751ba61281cc1c695742287
Reviewed-by: J-P Nurmi <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/quick/util/qquickutilmodule.cpp b/src/quick/util/qquickutilmodule.cpp
index 1d82cfca43..8ea903b010 100644
--- a/src/quick/util/qquickutilmodule.cpp
+++ b/src/quick/util/qquickutilmodule.cpp
@@ -53,6 +53,7 @@
 #include "qquickstate_p.h"
 #include "qquickstate_p_p.h"
 #include "qquicksystempalette_p.h"
+#include "qquicktextmetrics_p.h"
 #include "qquicktransition_p.h"
 #include "qquickanimator_p.h"
 #include <qqmlinfo.h>
@@ -109,4 +110,5 @@ void QQuickUtilModule::defineModule()
     qmlRegisterUncreatableType<QKeySequence, 2>("QtQuick", 2, 2, "StandardKey", QStringLiteral("Cannot create an instance of StandardKey."));
 
     qmlRegisterType<QQuickFontMetrics>("QtQuick", 2, 4, "FontMetrics");
+    qmlRegisterType<QQuickTextMetrics>("QtQuick", 2, 4, "TextMetrics");
 }