Port TextInput/TextEdit clipboard optimizations from QtQuick 2.0

Don't check if the clipboard has content until necessary as the
check can block for an extended period.

Port of 3db5afa71443533eee6825a5fb0da29498f96b94 from qtdeclarative.

Change-Id: I606af79cbf10b147aa1bb6c182b0a84aabbc5257
Reviewed-by: Martin Jones <martin.jones@jollamobile.com>

4 files changed, 32 insertions, 15 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativetextedit.cpp b/src/declarative/graphicsitems/qdeclarativetextedit.cpp
index 07ae0e95..ed65c8e8 100644
--- a/src/declarative/graphicsitems/qdeclarativetextedit.cpp
+++ b/src/declarative/graphicsitems/qdeclarativetextedit.cpp
@@ -1139,6 +1139,7 @@ void QDeclarativeTextEdit::setReadOnly(bool r)
     if (!r)
         d->control->moveCursor(QTextCursor::End);
 
+    q_canPasteChanged();
     emit readOnlyChanged(r);
 }
 
@@ -1508,6 +1509,10 @@ void QDeclarativeTextEdit::updateImgCache(const QRectF &rf)
 bool QDeclarativeTextEdit::canPaste() const
 {
     Q_D(const QDeclarativeTextEdit);
+    if (!d->canPasteValid) {
+        d->canPaste = d->control->canPaste();
+        d->canPasteValid = true;
+    }
     return d->canPaste;
 }
 
@@ -1565,9 +1570,7 @@ void QDeclarativeTextEditPrivate::init()
     QObject::connect(control, SIGNAL(microFocusChanged()), q, SLOT(moveCursorDelegate()));
     QObject::connect(control, SIGNAL(linkActivated(QString)), q, SIGNAL(linkActivated(QString)));
 #ifndef QT_NO_CLIPBOARD
-    QObject::connect(q, SIGNAL(readOnlyChanged(bool)), q, SLOT(q_canPasteChanged()));
     QObject::connect(QApplication::clipboard(), SIGNAL(dataChanged()), q, SLOT(q_canPasteChanged()));
-    canPaste = control->canPaste();
 #endif
 
     document = control->document();
@@ -1888,7 +1891,9 @@ void QDeclarativeTextEdit::q_canPasteChanged()
     Q_D(QDeclarativeTextEdit);
     bool old = d->canPaste;
     d->canPaste = d->control->canPaste();
-    if(old!=d->canPaste)
+    bool changed = old != d->canPaste || !d->canPasteValid;
+    d->canPasteValid = true;
+    if (changed)
         emit canPasteChanged();
 }
 
diff --git a/src/declarative/graphicsitems/qdeclarativetextedit_p_p.h b/src/declarative/graphicsitems/qdeclarativetextedit_p_p.h
index 9fb736ac..25f389f6 100644
--- a/src/declarative/graphicsitems/qdeclarativetextedit_p_p.h
+++ b/src/declarative/graphicsitems/qdeclarativetextedit_p_p.h
@@ -71,9 +71,10 @@ public:
       : color("black"), hAlign(QDeclarativeTextEdit::AlignLeft), vAlign(QDeclarativeTextEdit::AlignTop),
       imgDirty(true), dirty(false), richText(false), cursorVisible(false), focusOnPress(true),
       showInputPanelOnFocus(true), clickCausedFocus(false), persistentSelection(true), requireImplicitWidth(false),
-      hAlignImplicit(true), rightToLeftText(false), textMargin(0.0), lastSelectionStart(0), lastSelectionEnd(0),
+      hAlignImplicit(true), rightToLeftText(false), selectByMouse(false), canPaste(false), canPasteValid(false),
+      textMargin(0.0), lastSelectionStart(0), lastSelectionEnd(0),
       cursorComponent(0), cursor(0), format(QDeclarativeTextEdit::AutoText), document(0), wrapMode(QDeclarativeTextEdit::NoWrap),
-      mouseSelectionMode(QDeclarativeTextEdit::SelectCharacters), selectByMouse(false), canPaste(false),
+      mouseSelectionMode(QDeclarativeTextEdit::SelectCharacters),
       yoff(0)
     {
     }
@@ -112,6 +113,9 @@ public:
     bool requireImplicitWidth:1;
     bool hAlignImplicit:1;
     bool rightToLeftText:1;
+    bool selectByMouse : 1;
+    mutable bool canPaste : 1;
+    mutable bool canPasteValid : 1;
     qreal textMargin;
     int lastSelectionStart;
     int lastSelectionEnd;
@@ -123,8 +127,6 @@ public:
     QDeclarativeTextEdit::WrapMode wrapMode;
     QDeclarativeTextEdit::SelectionMode mouseSelectionMode;
     int lineCount;
-    bool selectByMouse;
-    bool canPaste;
     int yoff;
     QSize paintedSize;
 };
diff --git a/src/declarative/graphicsitems/qdeclarativetextinput.cpp b/src/declarative/graphicsitems/qdeclarativetextinput.cpp
index 8c13faeb..46f4b810 100644
--- a/src/declarative/graphicsitems/qdeclarativetextinput.cpp
+++ b/src/declarative/graphicsitems/qdeclarativetextinput.cpp
@@ -52,6 +52,7 @@
 #include <QFontMetrics>
 #include <QPainter>
 #include <QTextBoundaryFinder>
+#include <QMimeData>
 #include <qstyle.h>
 
 #ifndef QT_NO_LINEEDIT
@@ -454,6 +455,7 @@ void QDeclarativeTextInput::setReadOnly(bool ro)
     setFlag(QGraphicsItem::ItemAcceptsInputMethod, !ro);
     d->control->setReadOnly(ro);
 
+    q_canPasteChanged();
     emit readOnlyChanged(ro);
 }
 
@@ -1615,6 +1617,11 @@ void QDeclarativeTextInput::setMouseSelectionMode(SelectionMode mode)
 bool QDeclarativeTextInput::canPaste() const
 {
     Q_D(const QDeclarativeTextInput);
+    if (!d->canPasteValid) {
+        if (const QMimeData *mimeData = QApplication::clipboard()->mimeData())
+            d->canPaste = !d->control->isReadOnly() && mimeData->hasText();
+        d->canPasteValid = true;
+    }
     return d->canPaste;
 }
 
@@ -1867,11 +1874,8 @@ void QDeclarativeTextInputPrivate::init()
     q->connect(control, SIGNAL(updateNeeded(QRect)),
                q, SLOT(updateRect(QRect)));
 #ifndef QT_NO_CLIPBOARD
-    q->connect(q, SIGNAL(readOnlyChanged(bool)),
-            q, SLOT(q_canPasteChanged()));
     q->connect(QApplication::clipboard(), SIGNAL(dataChanged()),
             q, SLOT(q_canPasteChanged()));
-    canPaste = !control->isReadOnly() && QApplication::clipboard()->text().length() != 0;
 #endif // QT_NO_CLIPBOARD
     q->connect(control, SIGNAL(updateMicroFocus()),
                q, SLOT(updateCursorRectangle()));
@@ -1994,9 +1998,14 @@ void QDeclarativeTextInput::q_canPasteChanged()
     Q_D(QDeclarativeTextInput);
     bool old = d->canPaste;
 #ifndef QT_NO_CLIPBOARD
-    d->canPaste = !d->control->isReadOnly() && QApplication::clipboard()->text().length() != 0;
+    if (const QMimeData *mimeData = QApplication::clipboard()->mimeData())
+        d->canPaste = !d->control->isReadOnly() && mimeData->hasText();
+    else
+        d->canPaste = false;
 #endif
-    if(d->canPaste != old)
+    bool changed = d->canPaste != old || !d->canPasteValid;
+    d->canPasteValid = true;
+    if (changed)
         emit canPasteChanged();
 }
 
diff --git a/src/declarative/graphicsitems/qdeclarativetextinput_p_p.h b/src/declarative/graphicsitems/qdeclarativetextinput_p_p.h
index 13325f63..554fbc12 100644
--- a/src/declarative/graphicsitems/qdeclarativetextinput_p_p.h
+++ b/src/declarative/graphicsitems/qdeclarativetextinput_p_p.h
@@ -76,8 +76,8 @@ public:
                  mouseSelectionMode(QDeclarativeTextInput::SelectCharacters), inputMethodHints(Qt::ImhNone),
                  hscroll(0), oldScroll(0), oldValidity(false), focused(false), focusOnPress(true),
                  showInputPanelOnFocus(true), clickCausedFocus(false), cursorVisible(false),
-                 autoScroll(true), selectByMouse(false), canPaste(false), hAlignImplicit(true),
-                 selectPressed(false)
+                 autoScroll(true), selectByMouse(false), canPaste(false), canPasteValid(false)
+               , hAlignImplicit(true), selectPressed(false)
     {
     }
 
@@ -134,7 +134,8 @@ public:
     bool cursorVisible:1;
     bool autoScroll:1;
     bool selectByMouse:1;
-    bool canPaste:1;
+    mutable bool canPaste:1;
+    mutable bool canPasteValid:1;
     bool hAlignImplicit:1;
     bool selectPressed:1;