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Chemical Data Processing Library Python API - Version 1.2.0
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Chemical Data Processing Library Python API - Version 1.2.0
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An interface class with methods that provide information about the metrics of a font. More...
Inheritance diagram for CDPL.Vis.FontMetrics:Public Member Functions | |
| None | __init__ () |
| Initializes the FontMetrics instance. | |
| int | getObjectID () |
| Returns the numeric identifier (ID) of the wrapped C++ class instance. More... | |
| None | setFont (Font font) |
| Specifies the font for which to obtain the metrics. More... | |
| float | getAscent () |
| Returns the ascent of the font. More... | |
| float | getDescent () |
| Returns the descent of the font. More... | |
| float | getHeight () |
| Returns the height of the font. More... | |
| float | getLeading () |
| Returns the leading of the font. More... | |
| float | getWidth (str string) |
| None | getBounds (str string, Rectangle2D bounds) |
Properties | |
| objectID = property(getObjectID) | |
An interface class with methods that provide information about the metrics of a font.
Implementations of the FontMetrics interface provide height and width information for a given font and specific character glyphs in that font. Once a font has been specified with setFont(), there are several methods that operate on the font.
The methods
return basic size properties of the font. The ascent is the maximum amount by which characters ascend above the baseline, and the descent is the maximum amount by which characters descend below the baseline. The leading, or interline spacing, is the logical amount of space to be reserved between the descent of one line of text and the ascent of the next line. The height metric is the sum of the ascent and descent plus some implementation dependent extra space.
For single characters or strings, the advance width can be obtained by getWidth(). The advance width specifies the distance to a position on the baseline where the next character(s) should be drawn. A bounding rectangle large enough to contain the rendered glyph of a character, or a set of glyphs for a string, can be retrieved by getBounds().
| int CDPL.Vis.FontMetrics.getObjectID | ( | ) |
Returns the numeric identifier (ID) of the wrapped C++ class instance.
Different Python FontMetrics instances may reference the same underlying C++ class instance. The commonly used Python expression a is not b thus cannot tell reliably whether the two FontMetrics instances a and b reference different C++ objects. The numeric identifier returned by this method allows to correctly implement such an identity test via the simple expression a.getObjectID() != b.getObjectID().
| None CDPL.Vis.FontMetrics.setFont | ( | Font | font | ) |
Specifies the font for which to obtain the metrics.
| font | Specifies the font for which to retrieve the metrics. |
| float CDPL.Vis.FontMetrics.getAscent | ( | ) |
Returns the ascent of the font.
The ascent is the maximum distance from the baseline to the highest position characters extend to. Some font designers break this rule, e.g. when they put more than one accent on top of a character, or to accommodate an unusual character in an exotic language, so it is possible (though rare) that this value will be too small.
Reimplemented in CDPL.Vis.QtBackend.QtFontMetrics, and CDPL.Vis.CairoBackend.CairoFontMetrics.
| float CDPL.Vis.FontMetrics.getDescent | ( | ) |
Returns the descent of the font.
The descent is the distance from the baseline to the lowest position characters extend to. Some font designers break this rule, e.g. to accommodate an unusual character in an exotic language, so it is possible (though rare) that this value will be too small.
Reimplemented in CDPL.Vis.QtBackend.QtFontMetrics, and CDPL.Vis.CairoBackend.CairoFontMetrics.
| float CDPL.Vis.FontMetrics.getHeight | ( | ) |
Returns the height of the font.
The returned height is the sum of the ascent and descent plus some possible implementation dependent extra space.
Reimplemented in CDPL.Vis.QtBackend.QtFontMetrics, and CDPL.Vis.CairoBackend.CairoFontMetrics.
| float CDPL.Vis.FontMetrics.getLeading | ( | ) |
Returns the leading of the font.
The leading, or interline spacing, is the logical amount of space to be reserved between the descent of one line of text and the ascent of the next line.
Reimplemented in CDPL.Vis.QtBackend.QtFontMetrics, and CDPL.Vis.CairoBackend.CairoFontMetrics.
| float CDPL.Vis.FontMetrics.getWidth | ( | str | string | ) |
| string |
| None CDPL.Vis.FontMetrics.getBounds | ( | str | string, |
| Rectangle2D | bounds | ||
| ) |
| string | |
| bounds |
1.9.1