Added Terminal.getRangeAsHTML()

[Eugeny]

fixes #1883

[Tyriar]

I think this would fall into the same category as #2213 where we should defer this to an extension in order to keep the core slim. In order to do both properly we would need some way of exposing the color on IBufferCell if you want to propose an API for that that we can discuss?

[Eugeny]

I suppose you could expose methods to obtain cell attributes in BufferLineApiView?

[jerch]

How about this:

interface ... {
  // flags
  bold: boolean;
  underline: boolean;
  ...
  // colors
  fgColorMode: ColorModeEnum;  // enum reflecting CM_P16, CM_P256 and CM_RGB
  fgColor: number; // actual color number (-1 means default color)
  fgColorHex: string; // property for hex repr (empty string means default color)
}

Imho the number color value is needed to avoid costly number ---> hex conversions for every cell when comparing the values. (Maybe the same goes for the flag numbers, not sure).

Edit: If we expose only final hex colors from the current theme, we can omit the colorMode, and maybe the number value for color.

Edit2:
Adopted to the current API interface it might look like this:

interface IBufferCell {
  readonly char: string;
  readonly width: number;
  readonly color: IBufferCellColor;
  readonly flags: IBufferCellFlags;
}
interface IBufferCellColor {
  readonly fg: string;
  readonly bg: string;
}
interface IBufferCellFlags {
  readonly bold: boolean;
  readonly underline: boolean;
  ...
}

Edit3:
Lol 3rd edit - I think omitting the colorMode is no good idea as it will not work for an escape sequence output needed for #2213.

[Tyriar]

We could use union types for the color?

interface IBufferCell {
  readonly color: BufferCellColorAnsi16 | BufferCellColorAnsi256 | BufferCellColor24Bit;
}

[jerch]

@Tyriar Sure, just wondering how each type would look like?

[Tyriar]

Something like this?

interface IBufferCell {
	readonly color: IBufferCellColorAnsi16 | IBufferCellColorAnsi256 | IColor;
}

interface IBufferCellColorAnsi16 {
	ansi16Code: number;
	actualColor: IColor;
}

interface IBufferCellColorAnsi256 {
	ansi256Code: number;
	actualColor: IColor;
}

interface IColor {
	red: number;
	green: number;
	blue: number;
	hex: string;
}

[Tyriar]

Alternatively:

interface IBufferCell {
	readonly colorMode: ColorMode;
	/**
	 * Ansi16: 0-15
	 * Ansi256: 0-255
	 * TrueColor: 0 (or undefined?)
	 */
	readonly colorCode: number;
	readonly color: IColor;
}

enum ColorMode {
	Ansi16,
	Ansi256,
	TrueColor
}

interface IColor {
	red: number;
	green: number;
	blue: number;
	hex: string;
}

[jerch]

@Tyriar Hmm maybe the second one is easier to work with? For the first one I see troubles to distingish the color modes - this would only work by instanceof check or by explicit member checks against ansi16Code etc?

[Tyriar]

Yeah I'm leaning towards the second one too, moved this to #2225 and #2226

Let's close this off for now as the solution would look pretty different to this PR. @Eugeny would love your help on those APIs if you have bandwidth 😃