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Page color mode

PDFViewCtrl has three special color modes: night mode, inverted color mode, and custom color mode. In night mode, colors are adjusted to improve reading at night, in inverted color mode, all colors are inverted, and in custom color mode, you can set a custom color for text and the background color.

Color modes
Color modes from left to right: normal color mode, inverted color mode, night mode and custom color mode.

linkSet the color mode

To set the color mode:

  1. Find the constant value of the color mode

    Color modeConstant value
    Normal color modee_ptpostprocess_none
    Night modee_ptpostprocess_night_mode
    Inverted color modee_ptpostprocess_invert
    Custom color modee_ptpostprocess_gradient_map
  2. Call setColorPostProcessMode(_ mode: PTColorPostProcessMode).
  3. Optionally, set the PDFViewCtrl background color for the best visual result. You can set background color by calling setBackgroundColor(_ r: UInt8, g: UInt8, b: UInt8, a: UInt8).

    Background area

    For example, set the background color to black for night mode:

    pdfViewCtrl.setBackgroundColor(0, g: 0, b: 0, a: 255)
  4. If you are using postprocess_gradient_map, call setColorPostProcessColors(_ white_color: UIColor!, black_color: UIColor!) to set the white and black points. For example, for a sepia effect, try:

    let darkBrown = UIColor(red:0.24, green:0.15, blue:0.04, alpha:1.0)
    let lightBrown = UIColor(red:0.96, green:0.88, blue:0.79, alpha:1.0)
    pdfViewCtrl.setColorPostProcessColors(lightBrown, black_color: darkBrown)
  5. Update PDFViewCtrl to redraw the contents:

    pdfViewCtrl.update(true)

    Sample result when using postprocess_gradient_map and a light/dark brown for the white/black color: custom color mode

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