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| Returns a dummy [[:Category:gc|graphics context]].<br /> | | Returns a dummy [[:Category:gc|graphics context]].<br /> |
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| + | As a consequence, you are able to use the functions made for the "normal" [[:Category:gc|gc]]. |
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| It is typically used to measure pixel lengths and heights of strings when a normal graphics context is not available.<br /> | | It is typically used to measure pixel lengths and heights of strings when a normal graphics context is not available.<br /> |
| This may be the case when creating new text elements when the script app is initialized.<br /> | | This may be the case when creating new text elements when the script app is initialized.<br /> |
− | A graphics context is available only during paint events, and that may be too late to create and size the containers for text fields. | + | A graphics context is available only during paint events, and that may be too late to create and size the containers for text fields.<br /> |
| This graphics context cannot be used to draw graphics since it is not tied to a window. It can however do that if this gc is used in a function called within [[on.paint]]. | | This graphics context cannot be used to draw graphics since it is not tied to a window. It can however do that if this gc is used in a function called within [[on.paint]]. |
− | Here is an example of using the dummy graphics context to get the pixel length and height of a string.
| + | <br /> |
− | <syntaxhighlight>local gc = platform.gc() -- Get the dummy graphics context | |
− | gc:begin() -- Makes it the current graphics context
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− | local width = gc:getStringWidth(a_string) -- Gets the pixel length of a_string
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− | local height = gc:getStringHeight(a_string) -- Gets the pixel height of a_string
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| + | Here is an example of using the dummy graphics context to get the pixel length and height of a string : |
| + | <syntaxhighlight>local gc = platform.gc() -- Get the dummy graphics context |
| + | gc:begin() -- Makes it the current graphics context |
| + | local width = gc:getStringWidth(a_string) -- Gets the pixel length of a_string |
| + | local height = gc:getStringHeight(a_string) -- Gets the pixel height of a_string |
| -- do things here -- | | -- do things here -- |
− | gc:finish() -- Restores previous graphics context</syntaxhighlight> | + | gc:finish() -- Restores previous graphics context</syntaxhighlight> |
| It is important to use [[gc:begin]]() to set up the graphics context before using it in the getString routines and to call [[gc:finish]]() to relinquish it when finished with it. | | It is important to use [[gc:begin]]() to set up the graphics context before using it in the getString routines and to call [[gc:finish]]() to relinquish it when finished with it. |
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| {{Since|3.0}} | | {{Since|3.0}} |
| + | {{ObsoleteSince|3.2}} |
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− | [[Category:gc]] | + | [[Category:platform]] |