Do not bound explicit preferred size with implicit sizes. This
means that if Layout.preferredWidth was *explicitly* set to 50,
and Layout.maximumWidth had the implicit value 20, the effective
maximum width would be expanded to 50 in order to not disregard
the explicitly set preferred width. (covered by the tag
"expandMaxToExplicitPref" in test_sizeHint)

Note that this doesn't break any autotests, but the row layout
autotest was slightly changed to be able to add the new test cases.

This should make the behavior match the behavior of
QGraphicsGridLayout and QGraphicsLinearLayout

Change-Id: Ia23c8ef909827f14349906c003c72bb83689ef9a
Reviewed-by: Caroline Chao <caroline.chao@digia.com>
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

This reverts commit 91fc9b18

.

This patch got reverted because it broke the basiclayouts example on Mac OS.

However, the bug was in the basiclayouts example, so we can still add
this patch.

Change-Id: I97c3cf30dd5a5c97916b4811d8be0b5b5a7ebb4e
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

This reverts commit a4158c97d84d5c76126307213baf22d12babdbc2

This commit breaks the basiclayouts example so I am reverting it until we have a revised ifx.

Change-Id: I901924d292606ffe1e797232ad2f5ff02d8fc2d6
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

This was a bit inconsistent, because in the case of a Rectangle its
Layout.maximumWidth would return -1 by default (which was supposed to
be interpreted as infinity) However, since the maximumWidth propagated
up to the layout, the layout.Layout.maximumWidth would return
1000000000. Adding two Rectangles to the layout would make
layout.Layout.maximumWidth return 2000000000, and adding a third item
with Layout.maximumWidth:1 would make layout.Layout.maximumWidth
return 2000000001

With this change, since infinity + number = infinity, everything
that can grow to infinity will just return infinity.

In addition a developer can now more intuitively do comparisons
like this:

if (value > Layout.minimumWidth && value < Layout.maximumWidth)

instead of

if ((value == -1 || value > Layout.minimumWidth) &&
    (value != -1 && value < Layout.maximumWidth))

Now, as a bonus, it becomes less consistent to set an attached
(min,max) property to -1 in order to reset it to its implicit value.

This also fixes a documentation issue with regards to the attached
Layout.{min|max}imum{Width|Height} properties. It only told the story
correct if the item was not a layout, and updates the docs for the max
sizes to mention that it returns Number.POSITIVE_INFINITY

Change-Id: Ia638064fd3ed5614d7e496a9b5e4aa8fcb7307f7
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

When a layout did not have an implicit size nor any of the
Layout.preferred* properties set, the size hint calculation would
fall back to retrieving the width and the height properties of the
item. It would then store that value in the Layout.preferred*
property. This was wrong.

This could be a problem when an item was later added to the layout,
and consequently the implicit size of the layout got updated.
However, since the layout now had a preferred size set, a parent
layout would ignore the implicit size it had since it would settle
with the Layout.preferred* property (that's the rules the
effectiveSizeHint_helper work with).

The fix is to set the implicit width/height instead of the
Layout.preferred{width|height} property.

The compare in the test was actually by accident wrong, which can be
easily verified.

Change-Id: Ib9110dec7988a547441748698348227d1b8a077f
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

Change-Id: I9312c49f54cd231dd1129e1dbbed93aa959f67f0
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

These static function are only used by effectiveSizeHints_helper.
This broke because of commit 2b205db8



Change-Id: I189a59195d2576f4212b28fff4596bd803f25f49
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

The previous code was a bit rough in how it determined if the item
was supposed to be ignored or not.

For instance, it did not ignore items with
 Layout.maximumWidth: 0
or
 Layout.preferredWidth: 0
 Layout.fillWidth: false

The following patch will use
QQuickLayoutItem::effectiveSizeHints_helper. Since that is now shared,
it should make the behavior more consistent.

The patch also fixes a bug where ignored items (e.g. a hidden item)
was not re-added to the layout if it became visible again. (QTBUG-30796)
We use a QSet to keep track of the ignored items, and repopulate the
layout if any of the items in the QSet changed some properties relevant
for the layout.

Task-number: QTBUG-30796

Change-Id: Ia4b0584ed61e1b24efaca322551f6bb1a4228ca6
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

This enables us to find the effective size hints without allocating a
QQuickGridLayoutItem.

Change-Id: I827e3196c0a3979a2f6f5a0d6f3622cd6d121645
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>