tools/designer/src/lib/shared/qdesigner_widgetitem.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/designer/src/lib/shared/qdesigner_widgetitem.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,345 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Designer of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdesigner_widgetitem_p.h"
+#include "qdesigner_widget_p.h"
+#include "widgetfactory_p.h"
+
+#include <QtDesigner/QDesignerFormWindowInterface>
+#include <QtDesigner/QExtensionManager>
+#include <QtDesigner/QDesignerFormEditorInterface>
+#include <QtDesigner/QDesignerContainerExtension>
+#include <QtDesigner/QDesignerWidgetDataBaseInterface>
+
+#include <QtGui/QVBoxLayout>
+#include <QtGui/QHBoxLayout>
+#include <QtGui/QGridLayout>
+#include <QtGui/QFormLayout>
+#include <QtGui/QApplication>
+
+#include <QtCore/QTextStream>
+#include <QtCore/QDebug>
+#include <private/qlayout_p.h>
+
+QT_BEGIN_NAMESPACE
+
+enum { DebugWidgetItem = 0 };
+enum { MinimumLength = 10 };
+
+// Widget item creation function to be registered as factory method with
+// QLayoutPrivate
+static QWidgetItem *createDesignerWidgetItem(const QLayout *layout, QWidget *widget)
+{
+    Qt::Orientations orientations;
+    if (qdesigner_internal::QDesignerWidgetItem::check(layout, widget, &orientations)) {
+        if (DebugWidgetItem)
+            qDebug() << "QDesignerWidgetItem: Creating on " << layout << widget << orientations;
+        return new qdesigner_internal::QDesignerWidgetItem(layout, widget, orientations);
+    }
+    if (DebugWidgetItem)
+        qDebug() << "QDesignerWidgetItem: Noncontainer: " << layout << widget;
+
+    return 0;
+}
+
+static QString sizePolicyToString(const QSizePolicy &p)
+{
+    QString rc; {
+        QTextStream str(&rc);
+        str << "Control=" << p.controlType() << " expdirs=" << p.expandingDirections()
+            << " hasHeightForWidth=" << p.hasHeightForWidth()
+            << " H: Policy=" << p.horizontalPolicy()
+            << " stretch=" << p.horizontalStretch()
+            << " V: Policy=" << p.verticalPolicy()
+            << " stretch=" << p.verticalStretch();
+    }
+    return rc;
+}
+
+// Find the layout the item is contained in, recursing over
+// child layouts
+static const QLayout *findLayoutOfItem(const QLayout *haystack, const QLayoutItem *needle)
+{
+    const int count = haystack->count();
+    for (int i = 0; i < count; i++) {
+        QLayoutItem *item = haystack->itemAt(i);
+        if (item == needle)
+            return haystack;
+        if (QLayout *childLayout =  item->layout())
+            if (const QLayout *containing = findLayoutOfItem(childLayout, needle))
+                return containing;
+    }
+    return 0;
+}
+
+
+namespace qdesigner_internal {
+
+// ------------------ QDesignerWidgetItem
+QDesignerWidgetItem::QDesignerWidgetItem(const QLayout *containingLayout, QWidget *w, Qt::Orientations o) :
+    QWidgetItemV2(w),
+    m_orientations(o),
+    m_nonLaidOutMinSize(w->minimumSizeHint()),
+    m_nonLaidOutSizeHint(w->sizeHint()),
+    m_cachedContainingLayout(containingLayout)
+{
+    // Initialize the minimum size to prevent nonlaid-out frames/widgets
+    // from being slammed to zero
+    const QSize minimumSize = w->minimumSize();
+    if (!minimumSize.isEmpty())
+        m_nonLaidOutMinSize = minimumSize;
+    expand(&m_nonLaidOutMinSize);
+    expand(&m_nonLaidOutSizeHint);
+    w->installEventFilter(this);
+    connect(containingLayout, SIGNAL(destroyed()), this, SLOT(layoutChanged()));
+    if (DebugWidgetItem )
+        qDebug() << "QDesignerWidgetItem"  << w <<  sizePolicyToString(w->sizePolicy()) << m_nonLaidOutMinSize << m_nonLaidOutSizeHint;
+}
+
+void QDesignerWidgetItem::expand(QSize *s) const
+{
+    // Expand the size if its too small
+    if (m_orientations & Qt::Horizontal && s->width() <= 0)
+        s->setWidth(MinimumLength);
+    if (m_orientations & Qt::Vertical && s->height() <= 0)
+        s->setHeight(MinimumLength);
+}
+
+QSize QDesignerWidgetItem::minimumSize() const
+{
+    // Just track the size in case we are laid-out or stretched.
+    const QSize baseMinSize = QWidgetItemV2::minimumSize();
+    QWidget * w = constWidget();
+    if (w->layout() || subjectToStretch(containingLayout(), w)) {
+        m_nonLaidOutMinSize = baseMinSize;
+        return baseMinSize;
+    }
+    // Nonlaid out: Maintain last laid-out size
+    const QSize rc = baseMinSize.expandedTo(m_nonLaidOutMinSize);
+    if (DebugWidgetItem > 1)
+         qDebug() << "minimumSize" << constWidget() <<  baseMinSize << rc;
+    return rc;
+}
+
+QSize QDesignerWidgetItem::sizeHint()    const
+{
+    // Just track the size in case we are laid-out or stretched.
+    const QSize baseSizeHint = QWidgetItemV2::sizeHint();
+    QWidget * w = constWidget();
+    if (w->layout() || subjectToStretch(containingLayout(), w)) {
+        m_nonLaidOutSizeHint = baseSizeHint;
+        return baseSizeHint;
+    }
+    // Nonlaid out: Maintain last laid-out size
+    const QSize rc = baseSizeHint.expandedTo(m_nonLaidOutSizeHint);
+    if (DebugWidgetItem > 1)
+        qDebug() << "sizeHint" << constWidget() << baseSizeHint << rc;
+    return rc;
+}
+
+bool QDesignerWidgetItem::subjectToStretch(const QLayout *layout, QWidget *w)
+{
+    if (!layout)
+        return false;
+    // Are we under some stretch factor?
+    if (const QBoxLayout *bl = qobject_cast<const QBoxLayout *>(layout)) {
+        const int index = bl->indexOf(w);
+        Q_ASSERT(index != -1);
+        return bl->stretch(index) != 0;
+    }
+    if (const QGridLayout *cgl = qobject_cast<const QGridLayout *>(layout)) {
+        QGridLayout *gl = const_cast<QGridLayout *>(cgl);
+        const int index = cgl->indexOf(w);
+        Q_ASSERT(index != -1);
+        int row, column, rowSpan, columnSpan;
+        gl->getItemPosition (index, &row, &column, &rowSpan, &columnSpan);
+        const int rend = row + rowSpan;
+        const int cend = column + columnSpan;
+        for (int r = row; r < rend; r++)
+            if (cgl->rowStretch(r) != 0)
+                return true;
+        for (int c = column; c < cend; c++)
+            if (cgl->columnStretch(c) != 0)
+                return true;
+    }
+    return false;
+}
+
+/* Return the orientations mask for a layout, specifying
+ * in which directions squeezing should be prevented. */
+static Qt::Orientations layoutOrientation(const QLayout *layout)
+{
+    if (const QBoxLayout *bl = qobject_cast<const QBoxLayout *>(layout)) {
+        const QBoxLayout::Direction direction = bl->direction();
+        return direction == QBoxLayout::LeftToRight || direction == QBoxLayout::RightToLeft ? Qt::Horizontal : Qt::Vertical;
+    }
+    if (qobject_cast<const QFormLayout*>(layout))
+        return  Qt::Vertical;
+    return Qt::Horizontal|Qt::Vertical;
+}
+
+// Check for a non-container extension container
+bool  QDesignerWidgetItem::isContainer(const QDesignerFormEditorInterface *core, QWidget *w)
+{
+    if (!WidgetFactory::isFormEditorObject(w))
+        return false;
+    const QDesignerWidgetDataBaseInterface *wdb = core->widgetDataBase();
+    const int widx = wdb->indexOfObject(w);
+    if (widx == -1 || !wdb->item(widx)->isContainer())
+        return false;
+    if (qt_extension<QDesignerContainerExtension*>(core->extensionManager(), w))
+        return false;
+    return true;
+}
+
+bool QDesignerWidgetItem::check(const QLayout *layout, QWidget *w, Qt::Orientations *ptrToOrientations)
+{
+    // Check for form-editor non-containerextension-containers (QFrame, etc)
+    // within laid-out form editor widgets. No check for managed() here as we
+    // want container pages and widgets in the process of being morphed as
+    // well. Avoid nested layouts (as the effective stretch cannot be easily
+    // computed and may mess things up). Won't work for Q3 Group boxes.
+    if (ptrToOrientations)
+        *ptrToOrientations = 0;
+
+    const QObject *layoutParent = layout->parent();
+    if (!layoutParent || !layoutParent->isWidgetType() || !WidgetFactory::isFormEditorObject(layoutParent))
+        return false;
+
+    QDesignerFormWindowInterface *fw = QDesignerFormWindowInterface::findFormWindow(w);
+    if (!fw || !isContainer(fw->core(), w))
+        return false;
+
+    // If it is a box, restrict to its orientation
+    if (ptrToOrientations)
+        *ptrToOrientations = layoutOrientation(layout);
+
+    return true;
+}
+
+QSize QDesignerWidgetItem::nonLaidOutMinSize() const
+{
+    return m_nonLaidOutMinSize;
+}
+
+void QDesignerWidgetItem::setNonLaidOutMinSize(const QSize &s)
+{
+    if (DebugWidgetItem > 1)
+        qDebug() << "setNonLaidOutMinSize" << constWidget() << s;
+    m_nonLaidOutMinSize = s;
+}
+
+QSize QDesignerWidgetItem::nonLaidOutSizeHint() const
+{
+    return m_nonLaidOutSizeHint;
+}
+
+void QDesignerWidgetItem::setNonLaidOutSizeHint(const QSize &s)
+{
+    if (DebugWidgetItem > 1)
+        qDebug() << "setNonLaidOutSizeHint" << constWidget() << s;
+    m_nonLaidOutSizeHint = s;
+}
+
+void QDesignerWidgetItem::install()
+{
+    QLayoutPrivate::widgetItemFactoryMethod = createDesignerWidgetItem;
+}
+
+void QDesignerWidgetItem::deinstall()
+{
+    QLayoutPrivate::widgetItemFactoryMethod = 0;
+}
+
+const QLayout *QDesignerWidgetItem::containingLayout() const
+{
+    if (!m_cachedContainingLayout) {
+        if (QWidget *parentWidget = constWidget()->parentWidget())
+            if (QLayout *parentLayout = parentWidget->layout()) {
+                m_cachedContainingLayout = findLayoutOfItem(parentLayout, this);
+                if (m_cachedContainingLayout)
+                    connect(m_cachedContainingLayout, SIGNAL(destroyed()), this, SLOT(layoutChanged()));
+            }
+        if (DebugWidgetItem)
+            qDebug() << Q_FUNC_INFO << " found " << m_cachedContainingLayout << " after reparenting " << constWidget();
+    }
+    return m_cachedContainingLayout;
+}
+
+void QDesignerWidgetItem::layoutChanged()        
+{
+    if (DebugWidgetItem)
+        qDebug() << Q_FUNC_INFO;
+    m_cachedContainingLayout = 0;
+}
+
+bool QDesignerWidgetItem::eventFilter(QObject * /* watched */, QEvent *event)
+{    
+    if (event->type() == QEvent::ParentChange)
+        layoutChanged();
+    return false;
+}
+
+// ------------------   QDesignerWidgetItemInstaller
+
+int QDesignerWidgetItemInstaller::m_instanceCount = 0;
+
+QDesignerWidgetItemInstaller::QDesignerWidgetItemInstaller()
+{
+    if (m_instanceCount++ == 0) {
+        if (DebugWidgetItem)
+            qDebug() << "QDesignerWidgetItemInstaller: installing";
+        QDesignerWidgetItem::install();
+    }
+}
+
+QDesignerWidgetItemInstaller::~QDesignerWidgetItemInstaller()
+{
+    if (--m_instanceCount == 0) {
+        if (DebugWidgetItem)
+            qDebug() << "QDesignerWidgetItemInstaller: deinstalling";
+        QDesignerWidgetItem::deinstall();
+    }
+}
+
+}
+
+QT_END_NAMESPACE