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Diffstat (limited to 'src/layouts/qquickgridlayoutengine.cpp')
| -rw-r--r-- | src/layouts/qquickgridlayoutengine.cpp | 255 |
1 files changed, 0 insertions, 255 deletions
diff --git a/src/layouts/qquickgridlayoutengine.cpp b/src/layouts/qquickgridlayoutengine.cpp index 553f45d0..2c08eec1 100644 --- a/src/layouts/qquickgridlayoutengine.cpp +++ b/src/layouts/qquickgridlayoutengine.cpp @@ -40,261 +40,6 @@ QT_BEGIN_NAMESPACE -/* - The layout engine assumes: - 1. minimum <= preferred <= maximum - 2. descent is within minimum and maximum bounds (### verify) - - This function helps to ensure that by the following rules (in the following order): - 1. If minimum > maximum, set minimum = maximum - 2. Make sure preferred is not outside the [minimum,maximum] range. - 3. If descent > minimum, set descent = minimum (### verify if this is correct, it might - need some refinements to multiline texts) - - If any values are "not set" (i.e. negative), they will be left untouched, so that we - know which values needs to be fetched from the implicit hints (not user hints). - */ -static void normalizeHints(qreal &minimum, qreal &preferred, qreal &maximum, qreal &descent) -{ - if (minimum >= 0 && maximum >= 0 && minimum > maximum) - minimum = maximum; - - if (preferred >= 0) { - if (minimum >= 0 && preferred < minimum) { - preferred = minimum; - } else if (maximum >= 0 && preferred > maximum) { - preferred = maximum; - } - } - - if (minimum >= 0 && descent > minimum) - descent = minimum; -} - -static void boundSize(QSizeF &result, const QSizeF &size) -{ - if (size.width() >= 0 && size.width() < result.width()) - result.setWidth(size.width()); - if (size.height() >= 0 && size.height() < result.height()) - result.setHeight(size.height()); -} - -static void expandSize(QSizeF &result, const QSizeF &size) -{ - if (size.width() >= 0 && size.width() > result.width()) - result.setWidth(size.width()); - if (size.height() >= 0 && size.height() > result.height()) - result.setHeight(size.height()); -} - -static inline void combineHints(qreal ¤t, qreal fallbackHint) -{ - if (current < 0) - current = fallbackHint; -} - -static inline void combineSize(QSizeF &result, const QSizeF &fallbackSize) -{ - combineHints(result.rwidth(), fallbackSize.width()); - combineHints(result.rheight(), fallbackSize.height()); -} - -static inline void combineImplicitHints(QQuickLayoutAttached *info, Qt::SizeHint which, QSizeF *size) -{ - if (!info) return; - - Q_ASSERT(which == Qt::MinimumSize || which == Qt::MaximumSize); - - const QSizeF constraint(which == Qt::MinimumSize - ? QSizeF(info->minimumWidth(), info->minimumHeight()) - : QSizeF(info->maximumWidth(), info->maximumHeight())); - - if (!info->isExtentExplicitlySet(Qt::Horizontal, which)) - combineHints(size->rwidth(), constraint.width()); - if (!info->isExtentExplicitlySet(Qt::Vertical, which)) - combineHints(size->rheight(), constraint.height()); -} - -/*! - \internal - Note: Can potentially return the attached QQuickLayoutAttached object through \a attachedInfo. - - It is like this is because it enables it to be reused. - - The goal of this function is to return the effective minimum, preferred and maximum size hints - that the layout will use for this item. - This function takes care of gathering all explicitly set size hints, normalizes them so - that min < pref < max. - Further, the hints _not_explicitly_ set will then be initialized with the implicit size hints, - which is usually derived from the content of the layouts (or items). - - The following table illustrates the preference of the properties used for measuring layout - items. If present, the USER properties will be preferred. If USER properties are not present, - the HINT properties will be preferred. Finally, the FALLBACK properties will be used as an - ultimate fallback. - - Note that one can query if the value of Layout.minimumWidth or Layout.maximumWidth has been - explicitly or implicitly set with QQuickLayoutAttached::isExtentExplicitlySet(). This - determines if it should be used as a USER or as a HINT value. - - Fractional size hints will be ceiled to the closest integer. This is in order to give some - slack when the items are snapped to the pixel grid. - - | *Minimum* | *Preferred* | *Maximum* | -+----------------+----------------------+-----------------------+--------------------------+ -|USER (explicit) | Layout.minimumWidth | Layout.preferredWidth | Layout.maximumWidth | -|HINT (implicit) | Layout.minimumWidth | implicitWidth | Layout.maximumWidth | -|FALLBACK | 0 | width | Number.POSITIVE_INFINITY | -+----------------+----------------------+-----------------------+--------------------------+ - */ -void QQuickGridLayoutItem::effectiveSizeHints_helper(QQuickItem *item, QSizeF *cachedSizeHints, QQuickLayoutAttached **attachedInfo, bool useFallbackToWidthOrHeight) -{ - for (int i = 0; i < Qt::NSizeHints; ++i) - cachedSizeHints[i] = QSizeF(); - QQuickLayoutAttached *info = attachedLayoutObject(item, false); - // First, retrieve the user-specified hints from the attached "Layout." properties - if (info) { - struct Getters { - SizeGetter call[NSizes]; - }; - - static Getters horGetters = { - {&QQuickLayoutAttached::minimumWidth, &QQuickLayoutAttached::preferredWidth, &QQuickLayoutAttached::maximumWidth}, - }; - - static Getters verGetters = { - {&QQuickLayoutAttached::minimumHeight, &QQuickLayoutAttached::preferredHeight, &QQuickLayoutAttached::maximumHeight} - }; - for (int i = 0; i < NSizes; ++i) { - SizeGetter getter = horGetters.call[i]; - Q_ASSERT(getter); - - if (info->isExtentExplicitlySet(Qt::Horizontal, (Qt::SizeHint)i)) - cachedSizeHints[i].setWidth(qCeil((info->*getter)())); - - getter = verGetters.call[i]; - Q_ASSERT(getter); - if (info->isExtentExplicitlySet(Qt::Vertical, (Qt::SizeHint)i)) - cachedSizeHints[i].setHeight(qCeil((info->*getter)())); - } - } - - QSizeF &minS = cachedSizeHints[Qt::MinimumSize]; - QSizeF &prefS = cachedSizeHints[Qt::PreferredSize]; - QSizeF &maxS = cachedSizeHints[Qt::MaximumSize]; - QSizeF &descentS = cachedSizeHints[Qt::MinimumDescent]; - - // For instance, will normalize the following user-set hints - // from: [10, 5, 60] - // to: [10, 10, 60] - normalizeHints(minS.rwidth(), prefS.rwidth(), maxS.rwidth(), descentS.rwidth()); - normalizeHints(minS.rheight(), prefS.rheight(), maxS.rheight(), descentS.rheight()); - - // All explicit values gathered, now continue to gather the implicit sizes - - //--- GATHER MAXIMUM SIZE HINTS --- - combineImplicitHints(info, Qt::MaximumSize, &maxS); - combineSize(maxS, QSizeF(std::numeric_limits<qreal>::infinity(), std::numeric_limits<qreal>::infinity())); - // implicit max or min sizes should not limit an explicitly set preferred size - expandSize(maxS, prefS); - expandSize(maxS, minS); - - //--- GATHER MINIMUM SIZE HINTS --- - combineImplicitHints(info, Qt::MinimumSize, &minS); - expandSize(minS, QSizeF(0,0)); - boundSize(minS, prefS); - boundSize(minS, maxS); - - //--- GATHER PREFERRED SIZE HINTS --- - // First, from implicitWidth/Height - qreal &prefWidth = prefS.rwidth(); - qreal &prefHeight = prefS.rheight(); - if (prefWidth < 0 && item->implicitWidth() > 0) - prefWidth = qCeil(item->implicitWidth()); - if (prefHeight < 0 && item->implicitHeight() > 0) - prefHeight = qCeil(item->implicitHeight()); - - // If that fails, make an ultimate fallback to width/height - - if (!info && (prefWidth < 0 || prefHeight < 0)) - info = attachedLayoutObject(item); - - if (useFallbackToWidthOrHeight && info) { - /* This block is a bit hacky, but if we want to support using width/height - as preferred size hints in layouts, (which we think most people expect), - we only want to use the initial width. - This is because the width will change due to layout rearrangement, and the preferred - width should return the same value, regardless of the current width. - We therefore store the width in the implicitWidth attached property. - Since the layout listens to changes of implicitWidth, (it will - basically cause an invalidation of the layout), we have to disable that - notification while we set the implicit width (and height). - - Only use this fallback the first time the size hint is queried. Otherwise, we might - end up picking a width that is different than what was specified in the QML. - */ - if (prefWidth < 0 || prefHeight < 0) { - item->blockSignals(true); - if (prefWidth < 0) { - prefWidth = item->width(); - item->setImplicitWidth(prefWidth); - } - if (prefHeight < 0) { - prefHeight = item->height(); - item->setImplicitHeight(prefHeight); - } - item->blockSignals(false); - } - } - - - - // Normalize again after the implicit hints have been gathered - expandSize(prefS, minS); - boundSize(prefS, maxS); - - //--- GATHER DESCENT - // Minimum descent is only applicable for the effective minimum height, - // so we gather the descent last. - const qreal minimumDescent = minS.height() - item->baselineOffset(); - descentS.setHeight(minimumDescent); - - if (info) { - QMarginsF margins = info->qMargins(); - QSizeF extraMargins(margins.left() + margins.right(), margins.top() + margins.bottom()); - minS += extraMargins; - prefS += extraMargins; - maxS += extraMargins; - descentS += extraMargins; - } - if (attachedInfo) - *attachedInfo = info; -} - -/*! - \internal - - Assumes \a info is set (if the object has an attached property) - */ -QLayoutPolicy::Policy QQuickGridLayoutItem::effectiveSizePolicy_helper(QQuickItem *item, Qt::Orientation orientation, QQuickLayoutAttached *info) -{ - bool fillExtent = false; - bool isSet = false; - if (info) { - if (orientation == Qt::Horizontal) { - isSet = info->isFillWidthSet(); - if (isSet) fillExtent = info->fillWidth(); - } else { - isSet = info->isFillHeightSet(); - if (isSet) fillExtent = info->fillHeight(); - } - } - if (!isSet && qobject_cast<QQuickLayout*>(item)) - fillExtent = true; - return fillExtent ? QLayoutPolicy::Preferred : QLayoutPolicy::Fixed; - -} - void QQuickGridLayoutEngine::setAlignment(QQuickItem *quickItem, Qt::Alignment alignment) { if (QQuickGridLayoutItem *item = findLayoutItem(quickItem)) { |