Add line spacing to QTextBlockFormat, get/set functions, CSS support

The patch adds line spacing options to Qt, as in all modern word
processors. I primarily checked OpenOffice as a reference for how to
position the lines based on the various types of line spacing as well
as where to do the page breaks. The following functions were added:

void QTextBlockFormat::setLineHeight(qreal height, int heightType)
qreal QTextBlockFormat::lineHeight()
int QTextBlockFormat::lineHeightType()
qreal QTextBlockFormat::lineHeight(qreal scriptLineHeight, qreal scaling)

Here are the HeightTypes available:
QTextBlockFormat::SingleHeight
QTextBlockFormat::ProportionalHeight
QTextBlockFormat::FixedHeight
QTextBlockFormat::AtLeastHeight
QTextBlockFormat::LineDistanceHeight

The following CSS syntax was added:
line-height:150%
line-height:40px
line-height:normal
line-height:40al
line-height:40ld

Merge-request: 2305
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/src/gui/text/qtextformat.cpp b/src/gui/text/qtextformat.cpp
index 945b012..719db7a 100644
--- a/src/gui/text/qtextformat.cpp
+++ b/src/gui/text/qtextformat.cpp
@@ -541,6 +541,8 @@ Q_GUI_EXPORT QDataStream &operator>>(QDataStream &stream, QTextFormat &fmt)
     \value TabPositions     Specifies the tab positions.  The tab positions are structs of QTextOption::Tab which are stored in
                             a QList (internally, in a QList<QVariant>).
     \value BlockIndent
+    \value LineHeight
+    \value LineHeightType
     \value BlockNonBreakableLines
     \value BlockTrailingHorizontalRulerWidth The width of a horizontal ruler element.
 
@@ -1856,6 +1858,10 @@ QFont QTextCharFormat::font() const
     indentation is set with setIndent(), the indentation of the first
     line with setTextIndent().
 
+    Line spacing is set with setLineHeight() and retreived via lineHeight()
+    and lineHeightType(). The types of line spacing available are in the
+    LineHeightTypes enum.
+
     Line breaking can be enabled and disabled with setNonBreakableLines().
 
     The brush used to paint the paragraph's background
@@ -1872,6 +1878,22 @@ QFont QTextCharFormat::font() const
 */
 
 /*!
+    \since 4.7
+    \enum QTextBlockFormat::LineHeightTypes
+
+    This enum describes the various types of line spacing support paragraphs can have.
+
+    \value SingleHeight This is the default line height: single spacing.
+    \value ProportionalHeight This sets the spacing proportional to the line (in percentage).
+                              For example, set to 200 for double spacing.
+    \value FixedHeight This sets the line height to a fixed line height (in pixels).
+    \value AtLeastHeight This sets the minimum line height (in pixels).
+    \value LineDistanceHeight This adds the specified height between lines (in pixels).
+
+    \sa lineHeight(), lineHeightType(), setLineHeight()
+*/
+
+/*!
     \fn QTextBlockFormat::QTextBlockFormat()
 
     Constructs a new QTextBlockFormat.
@@ -2089,6 +2111,51 @@ QList<QTextOption::Tab> QTextBlockFormat::tabPositions() const
 
 
 /*!
+    \fn void QTextBlockFormat::setLineHeight(qreal height, int heightType)
+    \since 4.7
+
+    This sets the line height for the paragraph to the value in height
+    which is dependant on heightType, described by the LineHeightTypes enum.
+
+    \sa LineHeightTypes, lineHeight(), lineHeightType()
+*/
+
+
+/*!
+    \fn qreal QTextBlockFormat::lineHeight(qreal scriptLineHeight, qreal scaling) const
+    \since 4.7
+
+    This returns what the height of the lines in the paragraph will be depending
+    on the given height of the script line and the scaling. The value that is returned
+    is also dependant on the given LineHeightType of the paragraph as well as the LineHeight
+    setting that has been set for the paragraph. The scaling is needed for the heights
+    that include a fixed number of pixels, to scale them appropriately for printing.
+
+    \sa LineHeightTypes, setLineHeight(), lineHeightType()
+*/
+
+
+/*!
+    \fn qreal QTextBlockFormat::lineHeight() const
+    \since 4.7
+
+    This returns the LineHeight property for the paragraph.
+
+    \sa LineHeightTypes, setLineHeight(), lineHeightType()
+*/
+
+
+/*!
+    \fn qreal QTextBlockFormat::lineHeightType() const
+    \since 4.7
+
+    This returns the LineHeightType property of the paragraph.
+
+    \sa LineHeightTypes, setLineHeight(), lineHeight()
+*/
+
+
+/*!
     \fn void QTextBlockFormat::setNonBreakableLines(bool b)
 
     If \a b is true, the lines in the paragraph are treated as