Font: what changed
Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.
Title: Font
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| 1 | + | TFont class describes a typographic font information. The [[LCL]] defines the following [[Property|properties]]: | |
| 2 | + | ||
| 3 | + | ### Color | |
| 4 | + | ||
| 5 | + | Sets the [[Colors|colour]] of the text to be displayed. | |
| 6 | + | ||
| 7 | + | ### Height | |
| 8 | + | ||
| 9 | + | The height property specifies the font height in Pixels. | |
| 10 | + | ||
| 11 | + | However, due to Windows and Delphi compatibility, height might be described in 2 values, negative and positive. | |
| 12 | + | ||
| 13 | + | <figure> | |
| 14 | + | <img src="font_height.png" title="font_height.png" /> | |
| 15 | + | <figcaption>font_height.png</figcaption> | |
| 16 | + | </figure> | |
| 17 | + | ||
| 18 | + | Negative value takes into account only the height of font characters. | |
| 19 | + | ||
| 20 | + | Positive value takes into account height of font characters plus additional space on top of the font. (So, it would be possible to write a line of the text right after another, without adding any extra space, and the font would not look too densed). | |
| 21 | + | ||
| 22 | + | Normally, you want to use Negative font height. | |
| 23 | + | ||
| 24 | + | ### Name | |
| 25 | + | ||
| 26 | + | The name property defines the name of the font to be used. | |
| 27 | + | ||
| 28 | + | ### Pitch | |
| 29 | + | ||
| 30 | + | This property determines the spacing between the letters. It may have one of the following values: | |
| 31 | + | ||
| 32 | + | - *fpDefault* | |
| 33 | + | - *fpFixed* | |
| 34 | + | - *fxVariable* | |
| 35 | + | ||
| 36 | + | ### Size | |
| 37 | + | ||
| 38 | + | Is the size of the font in Typographic points. | |
| 39 | + | ||
| 40 | + | In order to convert from Typographic points to Pixels one should use a device (Screen or Printer) dots per point value (DPI) | |
| 41 | + | ||
| 42 | + | The size is also using Positive and Negative values, but in reverse order. | |
| 43 | + | ||
| 44 | + | Positive value takes into account only the height of font characters. (it's a typographic standard) | |
| 45 | + | ||
| 46 | + | Negative value takes into account height of font characters plus additional space on top of the font. (So, it would be possible to write a line of the text right after another, without adding any extra space, and the font would not look too dense). | |
| 47 | + | ||
| 48 | + | Normally, you want to use Positive font size values. | |
| 49 | + | ||
| 50 | + | It might be useful to note, that User Interface is typically presenting the size in typographs points. | |
| 51 | + | ||
| 52 | + | <figure> | |
| 53 | + | <img src="fontdialog.png" title="|toto" /> | |
| 54 | + | <figcaption>|toto</figcaption> | |
| 55 | + | </figure> | |
| 56 | + | ||
| 57 | + | In this example, the selected font would have Font.Size=16 | |
| 58 | + | ||
| 59 | + | #### Size to Height | |
| 60 | + | ||
| 61 | + | Once should use the following formal to convert from Size to height | |
| 62 | + | ||
| 63 | + | `Font.Height := -Font.Size * DPI / 72` | |
| 64 | + | ||
| 65 | + | and from Height to Size | |
| 66 | + | ||
| 67 | + | `Font.Size := -Font.Height / DPI * 72` | |
| 68 | + | ||
| 69 | + | Note, the use of negative , due to reverse logic. | |
| 70 | + | ||
| 71 | + | ### Style | |
| 72 | + | ||
| 73 | + | Defines the style of the text to be displayed or printed. | |
| 74 | + | ||
| 75 | + | --- | |
| 76 | + | *From the Free Pascal wiki, page "Font", as it stood on 2020-03-29 after a change by Jwdietrich, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* | |
| 77 | + | Category: GUI | |
| 78 | + | Category: LCL |