yage.gui.textblock

struct TextCursor ;

uint position ;

uint selectionStart ;

uint selectionEnd ;

struct TextBlock ;

Render text and simple html with styles to an image. TextBlock has two modes of input: setHtml() and the input() function that receives keypresses. This class is used internally by the engine. In most cases it shouldn't need to be called externally.

Vec!(2,int) cursorToXy (int position);

Get the xy pixel position of a cursor position. Functions for converting between line/letter/cursor space and x/y position.

int xyToCursor (Vec!(2,int) xy);

Get the cursor position from an xy pixel position. Functions for converting between line/letter/cursor space and x/y position.

int cursorToLine (ref int position);

Convert an absolute cursor position to a line/position pair.

Params:

int position

Character position from the beginning of the TextBlock After the function executes, this will be the position on the line returned.

Returns:
The line number. If position is after the last line, then the number of the last line is returned and position is an offset from this. Functions for converting between line/letter/cursor space and x/y position.

int lineToCursor (int line, int position);

Convert a cursor line/position pair to an absolute position.

Params:

int line
int position	Position from the beginning of the line, may be negative or exceed the line length.

Returns:
The absolute position of the cursor from the beginning of the text block. Functions for converting between line/letter/cursor space and x/y position.

char[] getHtml ();

Reverse the normal function of TextLayout and convert letters[] back to a string of html text. The text may use different tags than the original html, (since some information is lost) but will be functionally the same.

void input (int key, int mod, dchar unicode, ref TextCursor cursor);

Update lines and letters data structures from keyboard input

Params:

int key	SDL key code constant
int mod	modifier key.
dchar unicode	Unicode value of the pressed key.
TextCursor cursor	The Surface's TextCursor.

Image render (bool pow2 = false, TextCursor* cursor = null);

Convert a string of primitive html text and render it to an image. Note that this is currently not thread-safe, since the reusable buffers above make it non-re-entrant and also due to the non thread-safety of using Font. Characters with a bold font-weight are rendered at 1.5x normal width. Characters with a italic/oblique font-style are rendered skewed. For ideal rendering, instead use a font-family that has a bold or italic style.

Params:

style	A style with fontSize and lineHeight in terms of pixels
bool pow2	Render an image with dimensions that are a power of 2 (useful for older graphics cards)
TextCursor* cursor	Render this text cursor if not null .

Returns:
An RGBA image of width pixels wide and is shorter or equal to height. Note that the same buffer is used for each return, so one call to this function will overwrite a previous result.

void setHtml (char[] html);

Set the contents of the Textblock with html.

Params:

char[] html

String of utf-8 encoded html text to render. The following html tags are supported: a, b, br, del, i, span, sub, sup, u The following css is supported via inline style attributes: color, font-family, font-size[%|px], font-style[normal|italic|oblique], font-weight[normal|bold], letter-spacing[%|px], line-height[%|px], text-align[left|center|right] text-decoration[none|underline|overline|line-through]

bool update (Style style, int width, int height);

Replace the text with new text, rebuilding the internal lines and letters data structures. This is unlike input(), which modifies the text based on a single keystroke.

Params:

Style style	A style with fontSize and lineHeight in terms of pixels
int width	Available width for rendering text
int height	Available height for rendering text.

Returns:
True if the text will need to be re-rendered, false otherwise.

TODO:
Should this be a constructor to maintain RAII?