QFontMetricsF¶
The
QFontMetricsF
class provides font metrics information. More…
Synopsis¶
Functions¶
def
__eq__
(other)def
__ne__
(other)def
ascent
()def
averageCharWidth
()def
boundingRect
(r, flags, string[, tabstops=0[, tabarray=None]])def
boundingRect
(string)def
boundingRectChar
(arg__1)def
capHeight
()def
descent
()def
elidedText
(text, mode, width[, flags=0])def
fontDpi
()def
height
()def
horizontalAdvance
(arg__1)def
horizontalAdvance
(string[, length=-1])def
inFont
(arg__1)def
inFontUcs4
(ucs4)def
leading
()def
leftBearing
(arg__1)def
lineSpacing
()def
lineWidth
()def
maxWidth
()def
minLeftBearing
()def
minRightBearing
()def
operator=
(arg__1)def
overlinePos
()def
rightBearing
(arg__1)def
size
(flags, str[, tabstops=0[, tabarray=None]])def
strikeOutPos
()def
swap
(other)def
tightBoundingRect
(text)def
underlinePos
()def
width
(string)def
widthChar
(arg__1)def
xHeight
()
Detailed Description¶
QFontMetricsF
functions calculate the size of characters and strings for a given font. You can construct aQFontMetricsF
object with an existingQFont
to obtain metrics for that font. If the font is changed later, the font metrics object is not updated.Once created, the object provides functions to access the individual metrics of the font, its characters, and for strings rendered in the font.
There are several functions that operate on the font:
ascent()
,descent()
,height()
,leading()
andlineSpacing()
return the basic size properties of the font. TheunderlinePos()
,overlinePos()
,strikeOutPos()
andlineWidth()
functions, return the properties of the line that underlines, overlines or strikes out the characters. These functions are all fast.There are also some functions that operate on the set of glyphs in the font:
minLeftBearing()
,minRightBearing()
andmaxWidth()
. These are by necessity slow, and we recommend avoiding them if possible.For each character, you can get its
horizontalAdvance()
,leftBearing()
, andrightBearing()
, and find out whether it is in the font usinginFont()
. You can also treat the character as a string, and use the string functions on it.The string functions include
horizontalAdvance()
, to return the width of a string in pixels (or points, for a printer),boundingRect()
, to return a rectangle large enough to contain the rendered string, andsize()
, to return the size of that rectangle.Example:
font = QFont("times", 24) fm = QFontMetricsF(font) pixelsWide = fm.width("What's the width of this text?") pixelsHigh = fm.height()See also
- class PySide2.QtGui.QFontMetricsF(font)¶
PySide2.QtGui.QFontMetricsF(font, pd)
PySide2.QtGui.QFontMetricsF(arg__1)
PySide2.QtGui.QFontMetricsF(arg__1)
- Parameters:
font –
PySide2.QtGui.QFont
arg__1 –
PySide2.QtGui.QFontMetrics
- PySide2.QtGui.QFontMetricsF.ascent()¶
- Return type:
float
Returns the ascent of the font.
The ascent of a font is the distance from the baseline to the highest position characters extend to. In practice, some font designers break this rule, e.g. when they put more than one accent on top of a character, or to accommodate a certain character, so it is possible (though rare) that this value will be too small.
See also
- PySide2.QtGui.QFontMetricsF.averageCharWidth()¶
- Return type:
float
Returns the average width of glyphs in the font.
- PySide2.QtGui.QFontMetricsF.boundingRect(r, flags, string[, tabstops=0[, tabarray=None]])¶
- Parameters:
flags – int
string – str
tabstops – int
tabarray – int
- Return type:
This is an overloaded function.
Returns the bounding rectangle of the characters in the given
text
. This is the set of pixels the text would cover if drawn when constrained to the bounding rectangle specified byrect
. Ifrect
is a reference to aNone
object, e.g. when passing a default constructedQRectF
, the bounding rectangle will not constrain itself to the size.The
flags
argument is the bitwise OR of the following flags:AlignLeft
aligns to the left border, except for Arabic and Hebrew where it aligns to the right.AlignRight
aligns to the right border, except for Arabic and Hebrew where it aligns to the left.AlignJustify
produces justified text.AlignHCenter
aligns horizontally centered.AlignTop
aligns to the top border.AlignBottom
aligns to the bottom border.AlignVCenter
aligns vertically centeredAlignCenter
(==Qt::AlignHCenter | Qt::AlignVCenter
)TextSingleLine
ignores newline characters in the text.TextExpandTabs
expands tabs (see below)TextShowMnemonic
interprets “&x” as x; i.e., underlined.TextWordWrap
breaks the text to fit the rectangle.
Horizontal
alignment defaults toAlignLeft
and vertical alignment defaults toAlignTop
.If several of the horizontal or several of the vertical alignment flags are set, the resulting alignment is undefined.
These flags are defined in
AlignmentFlag
.If
TextExpandTabs
is set inflags
, the following behavior is used to interpret tab characters in the text:If
tabArray
is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs in the text.If
tabStops
is non-zero, it is used as the tab spacing (in pixels).
Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts.
Newline characters are processed as line breaks.
Despite the different actual character heights, the heights of the bounding rectangles of “Yes” and “yes” are the same.
The bounding rectangle returned by this function is somewhat larger than that calculated by the simpler
boundingRect()
function. This function uses themaximum left
andright
font bearings as is necessary for multi-line text to align correctly. Also, fontHeight() andlineSpacing()
are used to calculate the height, rather than individual character heights.See also
horizontalAdvance()
boundingRect()
Alignment
- PySide2.QtGui.QFontMetricsF.boundingRect(string)
- Parameters:
string – str
- Return type:
- PySide2.QtGui.QFontMetricsF.boundingRectChar(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
Returns the bounding rectangle of the character
ch
relative to the left-most point on the base line.Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts, and that the text output may cover all pixels in the bounding rectangle.
Note that the rectangle usually extends both above and below the base line.
See also
- PySide2.QtGui.QFontMetricsF.capHeight()¶
- Return type:
float
Returns the cap height of the font.
The cap height of a font is the height of a capital letter above the baseline. It specifically is the height of capital letters that are flat - such as H or I - as opposed to round letters such as O, or pointed letters like A, both of which may display overshoot.
See also
- PySide2.QtGui.QFontMetricsF.descent()¶
- Return type:
float
Returns the descent of the font.
The descent is the distance from the base line to the lowest point characters extend to. (Note that this is different from X, which adds 1 pixel.) In practice, some font designers break this rule, e.g. to accommodate a certain character, so it is possible (though rare) that this value will be too small.
See also
- PySide2.QtGui.QFontMetricsF.elidedText(text, mode, width[, flags=0])¶
- Parameters:
text – str
mode –
TextElideMode
width – float
flags – int
- Return type:
str
If the string
text
is wider thanwidth
, returns an elided version of the string (i.e., a string with “…” in it). Otherwise, returns the original string.The
mode
parameter specifies whether the text is elided on the left (for example, “…tech”), in the middle (for example, “Tr…ch”), or on the right (for example, “Trol…”).The
width
is specified in pixels, not characters.The
flags
argument is optional and currently only supportsTextShowMnemonic
as value.The elide mark follows the
layoutdirection
. For example, it will be on the right side of the text for right-to-left layouts if themode
isQt::ElideLeft
, and on the left side of the text if themode
isQt::ElideRight
.
- PySide2.QtGui.QFontMetricsF.fontDpi()¶
- Return type:
float
Returns the font DPI.
- PySide2.QtGui.QFontMetricsF.height()¶
- Return type:
float
Returns the height of the font.
This is always equal to
ascent()
+descent()
.See also
- PySide2.QtGui.QFontMetricsF.horizontalAdvance(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
float
This is an overloaded function.
Returns the horizontal advance of character
ch
in pixels. This is a distance appropriate for drawing a subsequent character afterch
.Some of the metrics are described in the image to the right. The central dark rectangles cover the logical
horizontalAdvance()
of each character. The outer pale rectangles cover theleftBearing()
andrightBearing()
of each character. Notice that the bearings of “f” in this particular font are both negative, while the bearings of “o” are both positive.Warning
This function will produce incorrect results for Arabic characters or non-spacing marks in the middle of a string, as the glyph shaping and positioning of marks that happens when processing strings cannot be taken into account. When implementing an interactive text control, use
QTextLayout
instead.See also
- PySide2.QtGui.QFontMetricsF.horizontalAdvance(string[, length=-1])
- Parameters:
string – str
length – int
- Return type:
float
Returns the horizontal advance in pixels of the first
length
characters oftext
. Iflength
is negative (the default), the entire string is used.The advance is the distance appropriate for drawing a subsequent character after
text
.See also
- PySide2.QtGui.QFontMetricsF.inFont(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
bool
Returns
true
if characterch
is a valid character in the font; otherwise returnsfalse
.
- PySide2.QtGui.QFontMetricsF.inFontUcs4(ucs4)¶
- Parameters:
ucs4 –
uint
- Return type:
bool
Returns
true
if the character given bych
, encoded in UCS-4/UTF-32, is a valid character in the font; otherwise returnsfalse
.
- PySide2.QtGui.QFontMetricsF.leading()¶
- Return type:
float
Returns the leading of the font.
This is the natural inter-line spacing.
See also
- PySide2.QtGui.QFontMetricsF.leftBearing(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
float
Returns the left bearing of character
ch
in the font.The left bearing is the right-ward distance of the left-most pixel of the character from the logical origin of the character. This value is negative if the pixels of the character extend to the left of the logical origin.
See
horizontalAdvance()
for a graphical description of this metric.
- PySide2.QtGui.QFontMetricsF.lineSpacing()¶
- Return type:
float
Returns the distance from one base line to the next.
- PySide2.QtGui.QFontMetricsF.lineWidth()¶
- Return type:
float
Returns the width of the underline and strikeout lines, adjusted for the point size of the font.
See also
- PySide2.QtGui.QFontMetricsF.maxWidth()¶
- Return type:
float
Returns the width of the widest character in the font.
- PySide2.QtGui.QFontMetricsF.minLeftBearing()¶
- Return type:
float
Returns the minimum left bearing of the font.
This is the smallest
leftBearing
(char) of all characters in the font.Note that this function can be very slow if the font is large.
See also
- PySide2.QtGui.QFontMetricsF.minRightBearing()¶
- Return type:
float
Returns the minimum right bearing of the font.
This is the smallest
rightBearing
(char) of all characters in the font.Note that this function can be very slow if the font is large.
See also
- PySide2.QtGui.QFontMetricsF.__ne__(other)¶
- Parameters:
other –
PySide2.QtGui.QFontMetricsF
- Return type:
bool
This is an overloaded function.
Returns
true
if the font metrics are not equal to theother
font metrics; otherwise returnsfalse
.See also
operator==()
- PySide2.QtGui.QFontMetricsF.operator=(arg__1)
- Parameters:
arg__1 –
PySide2.QtGui.QFontMetrics
- Return type:
- PySide2.QtGui.QFontMetricsF.__eq__(other)¶
- Parameters:
other –
PySide2.QtGui.QFontMetricsF
- Return type:
bool
Returns
true
if the font metrics are equal to theother
font metrics; otherwise returnsfalse
.Two font metrics are considered equal if they were constructed from the same
QFont
and the paint devices they were constructed for are considered to be compatible.
- PySide2.QtGui.QFontMetricsF.overlinePos()¶
- Return type:
float
Returns the distance from the base line to where an overline should be drawn.
See also
- PySide2.QtGui.QFontMetricsF.rightBearing(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
float
Returns the right bearing of character
ch
in the font.The right bearing is the left-ward distance of the right-most pixel of the character from the logical origin of a subsequent character. This value is negative if the pixels of the character extend to the right of the
horizontalAdvance()
of the character.See
horizontalAdvance()
for a graphical description of this metric.
- PySide2.QtGui.QFontMetricsF.size(flags, str[, tabstops=0[, tabarray=None]])¶
- Parameters:
flags – int
str – str
tabstops – int
tabarray – int
- Return type:
Returns the size in pixels of the characters in the given
text
.The
flags
argument is the bitwise OR of the following flags:TextSingleLine
ignores newline characters.TextExpandTabs
expands tabs (see below)TextShowMnemonic
interprets “&x” as x; i.e., underlined.TextWordWrap
breaks the text to fit the rectangle.
These flags are defined in the
TextFlag
enum.If
TextExpandTabs
is set inflags
, the following behavior is used to interpret tab characters in the text:If
tabArray
is non-null, it specifies a 0-terminated sequence of pixel-positions for tabs in the text.If
tabStops
is non-zero, it is used as the tab spacing (in pixels).
Newline characters are processed as line breaks.
Note: Despite the different actual character heights, the heights of the bounding rectangles of “Yes” and “yes” are the same.
See also
- PySide2.QtGui.QFontMetricsF.strikeOutPos()¶
- Return type:
float
Returns the distance from the base line to where the strikeout line should be drawn.
See also
- PySide2.QtGui.QFontMetricsF.swap(other)¶
- Parameters:
other –
PySide2.QtGui.QFontMetricsF
Swaps this font metrics instance with
other
. This function is very fast and never fails.
- PySide2.QtGui.QFontMetricsF.tightBoundingRect(text)¶
- Parameters:
text – str
- Return type:
Returns a tight bounding rectangle around the characters in the string specified by
text
. The bounding rectangle always covers at least the set of pixels the text would cover if drawn at (0, 0).Note that the bounding rectangle may extend to the left of (0, 0), e.g. for italicized fonts, and that the width of the returned rectangle might be different than what the
horizontalAdvance()
method returns.If you want to know the advance width of the string (to lay out a set of strings next to each other), use
horizontalAdvance()
instead.Newline characters are processed as normal characters, not as linebreaks.
Warning
Calling this method is very slow on Windows.
See also
- PySide2.QtGui.QFontMetricsF.underlinePos()¶
- Return type:
float
Returns the distance from the base line to where an underscore should be drawn.
See also
- PySide2.QtGui.QFontMetricsF.width(string)¶
- Parameters:
string – str
- Return type:
float
- PySide2.QtGui.QFontMetricsF.widthChar(arg__1)¶
- Parameters:
arg__1 –
QChar
- Return type:
float
This is an overloaded function.
Returns the logical width of character
ch
in pixels. This is a distance appropriate for drawing a subsequent character afterch
.Some of the metrics are described in the image to the right. The central dark rectangles cover the logical
width()
of each character. The outer pale rectangles cover theleftBearing()
andrightBearing()
of each character. Notice that the bearings of “f” in this particular font are both negative, while the bearings of “o” are both positive.in Qt 5.11. Use
horizontalAdvance()
instead.Warning
This function will produce incorrect results for Arabic characters or non-spacing marks in the middle of a string, as the glyph shaping and positioning of marks that happens when processing strings cannot be taken into account. When implementing an interactive text control, use
QTextLayout
instead.See also
- PySide2.QtGui.QFontMetricsF.xHeight()¶
- Return type:
float
Returns the ‘x’ height of the font. This is often but not always the same as the height of the character ‘x’.
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