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import foundation
import uikit
import quartzcore
import coregraphics
import accelerate
public enum uiimagecontentmode {
case scaletofill, scaleaspectfit, scaleaspectfill
}
public extension uiimage {
/**
a singleton shared nsurl cache used for images from url
*/
static var shared: nscache! {
struct staticsharedcache {
static var shared: nscache? = nscache()
}
return staticsharedcache.shared!
}
// mark: image from solid color
/**
creates a new solid color image.
- parameter color: the color to fill the image with.
- parameter size: image size (defaults: 10x10)
- returns a new image
*/
convenience init?(color: uicolor, size: cgsize = cgsize(width: 10, height: 10)) {
let rect = cgrect(x: 0, y: 0, width: size.width, height: size.height)
uigraphicsbeginimagecontextwithoptions(rect.size, false, 0)
let context = uigraphicsgetcurrentcontext()
context?.setfillcolor(color.cgcolor)
context?.fill(rect)
self.init(cgimage:(uigraphicsgetimagefromcurrentimagecontext()?.cgimage!)!)
uigraphicsendimagecontext()
}
// mark: image from gradient colors
/**
creates a gradient color image.
- parameter gradientcolors: an array of colors to use for the gradient.
- parameter size: image size (defaults: 10x10)
- returns a new image
*/
convenience init?(gradientcolors:[uicolor], size:cgsize = cgsize(width: 10, height: 10), locations: [float] = [] )
{
uigraphicsbeginimagecontextwithoptions(size, false, 0)
let context = uigraphicsgetcurrentcontext()
let colorspace = cgcolorspacecreatedevicergb()
let colors = gradientcolors.map {(color: uicolor) -> anyobject! in return color.cgcolor as anyobject! } as nsarray
let gradient: cggradient
if locations.count > 0 {
let cglocations = locations.map { cgfloat($0) }
gradient = cggradient(colorsspace: colorspace, colors: colors, locations: cglocations)!
} else {
gradient = cggradient(colorsspace: colorspace, colors: colors, locations: nil)!
}
context!.drawlineargradient(gradient, start: cgpoint(x: 0, y: 0), end: cgpoint(x: 0, y: size.height), options: cggradientdrawingoptions(rawvalue: 0))
self.init(cgimage:(uigraphicsgetimagefromcurrentimagecontext()?.cgimage!)!)
uigraphicsendimagecontext()
}
/**
applies gradient color overlay to an image.
- parameter gradientcolors: an array of colors to use for the gradient.
- parameter locations: an array of locations to use for the gradient.
- parameter blendmode: the blending type to use.
- returns a new image
*/
func apply(gradientcolors: [uicolor], locations: [float] = [], blendmode: cgblendmode = cgblendmode.normal) -> uiimage
{
uigraphicsbeginimagecontextwithoptions(size, false, scale)
let context = uigraphicsgetcurrentcontext()
context?.translateby(x: 0, y: size.height)
context?.scaleby(x: 1.0, y: -1.0)
context?.setblendmode(blendmode)
let rect = cgrect(x: 0, y: 0, width: size.width, height: size.height)
context?.draw(self.cgimage!, in: rect)
// create gradient
let colorspace = cgcolorspacecreatedevicergb()
let colors = gradientcolors.map {(color: uicolor) -> anyobject! in return color.cgcolor as anyobject! } as nsarray
let gradient: cggradient
if locations.count > 0 {
let cglocations = locations.map { cgfloat($0) }
gradient = cggradient(colorsspace: colorspace, colors: colors, locations: cglocations)!
} else {
gradient = cggradient(colorsspace: colorspace, colors: colors, locations: nil)!
}
// apply gradient
context?.clip(to: rect, mask: self.cgimage!)
context?.drawlineargradient(gradient, start: cgpoint(x: 0, y: 0), end: cgpoint(x: 0, y: size.height), options: cggradientdrawingoptions(rawvalue: 0))
let image = uigraphicsgetimagefromcurrentimagecontext()
uigraphicsendimagecontext();
return image!;
}
// mark: image with text
/**
creates a text label image.
- parameter text: the text to use in the label.
- parameter font: the font (default: system font of size 18)
- parameter color: the text color (default: white)
- parameter backgroundcolor: the background color (default:gray).
- parameter size: image size (default: 10x10)
- parameter offset: center offset (default: 0x0)
- returns a new image
*/
convenience init?(text: string, font: uifont = uifont.systemfont(ofsize: 18), color: uicolor = uicolor.white, backgroundcolor: uicolor = uicolor.gray, size: cgsize = cgsize(width: 100, height: 100), offset: cgpoint = cgpoint(x: 0, y: 0)) {
let label = uilabel(frame: cgrect(x: 0, y: 0, width: size.width, height: size.height))
label.font = font
label.text = text
label.textcolor = color
label.textalignment = .center
label.backgroundcolor = backgroundcolor
let image = uiimage(fromview: label)
uigraphicsbeginimagecontextwithoptions(size, false, 0)
image?.draw(in: cgrect(x: 0, y: 0, width: size.width, height: size.height))
self.init(cgimage:(uigraphicsgetimagefromcurrentimagecontext()?.cgimage!)!)
uigraphicsendimagecontext()
}
// mark: image from uiview
/**
creates an image from a uiview.
- parameter fromview: the source view.
- returns a new image
*/
convenience init?(fromview view: uiview) {
uigraphicsbeginimagecontextwithoptions(view.bounds.size, false, 0)
//view.drawviewhierarchyinrect(view.bounds, afterscreenupdates: true)
view.layer.render(in: uigraphicsgetcurrentcontext()!)
self.init(cgimage:(uigraphicsgetimagefromcurrentimagecontext()?.cgimage!)!)
uigraphicsendimagecontext()
}
// mark: image with radial gradient
// radial background originally from: https://developer.apple.com/library/ios/#documentation/graphicsimaging/conceptual/drawingwithquartz2d/dq_shadings/dq_shadings.html
/**
creates a radial gradient.
- parameter startcolor: the start color
- parameter endcolor: the end color
- parameter radialgradientcenter: the gradient center (default:0.5,0.5).
- parameter radius: radius size (default: 0.5)
- parameter size: image size (default: 100x100)
- returns a new image
*/
convenience init?(startcolor: uicolor, endcolor: uicolor, radialgradientcenter: cgpoint = cgpoint(x: 0.5, y: 0.5), radius: float = 0.5, size: cgsize = cgsize(width: 100, height: 100)) {
uigraphicsbeginimagecontextwithoptions(size, true, 0)
let num_locations: int = 2
let locations: [cgfloat] = [0.0, 1.0] as [cgfloat]
let startcomponents = startcolor.cgcolor.components!
let endcomponents = endcolor.cgcolor.components!
let components: [cgfloat] = [startcomponents[0], startcomponents[1], startcomponents[2], startcomponents[3], endcomponents[0], endcomponents[1], endcomponents[2], endcomponents[3]]
let colorspace = cgcolorspacecreatedevicergb()
let gradient = cggradient(colorspace: colorspace, colorcomponents: components, locations: locations, count: num_locations)
// normalize the 0-1 ranged inputs to the width of the image
let acenter = cgpoint(x: radialgradientcenter.x * size.width, y: radialgradientcenter.y * size.height)
let aradius = cgfloat(min(size.width, size.height)) * cgfloat(radius)
// draw it
uigraphicsgetcurrentcontext()?.drawradialgradient(gradient!, startcenter: acenter, startradius: 0, endcenter: acenter, endradius: aradius, options: cggradientdrawingoptions.drawsafterendlocation)
self.init(cgimage:(uigraphicsgetimagefromcurrentimagecontext()?.cgimage!)!)
// clean up
uigraphicsendimagecontext()
}
// mark: alpha
/**
returns true if the image has an alpha layer.
*/
var hasalpha: bool {
let alpha: cgimagealphainfo = self.cgimage!.alphainfo
switch alpha {
case .first, .last, .premultipliedfirst, .premultipliedlast:
return true
default:
return false
}
}
/**
returns a copy of the given image, adding an alpha channel if it doesn't already have one.
*/
func applyalpha() -> uiimage? {
if hasalpha {
return self
}
let imageref = self.cgimage;
let width = imageref?.width;
let height = imageref?.height;
let colorspace = imageref?.colorspace
// the bitspercomponent and bitmapinfo values are hard-coded to prevent an "unsupported parameter combination" error
let bitmapinfo = cgbitmapinfo(rawvalue: cgbitmapinfo().rawvalue | cgimagealphainfo.premultipliedfirst.rawvalue)
let offscreencontext = cgcontext(data: nil, width: width!, height: height!, bitspercomponent: 8, bytesperrow: 0, space: colorspace!, bitmapinfo: bitmapinfo.rawvalue)
// draw the image into the context and retrieve the new image, which will now have an alpha layer
let rect: cgrect = cgrect(x: 0, y: 0, width: cgfloat(width!), height: cgfloat(height!))
offscreencontext?.draw(imageref!, in: rect)
let imagewithalpha = uiimage(cgimage: (offscreencontext?.makeimage()!)!)
return imagewithalpha
}
/**
returns a copy of the image with a transparent border of the given size added around its edges. i.e. for rotating an image without getting jagged edges.
- parameter padding: the padding amount.
- returns a new image.
*/
func apply(padding: cgfloat) -> uiimage? {
// if the image does not have an alpha layer, add one
let image = self.applyalpha()
if image == nil {
return nil
}
let rect = cgrect(x: 0, y: 0, width: size.width + padding * 2, height: size.height + padding * 2)
// build a context that's the same dimensions as the new size
let colorspace = self.cgimage?.colorspace
let bitmapinfo = self.cgimage?.bitmapinfo
let bitspercomponent = self.cgimage?.bitspercomponent
let context = cgcontext(data: nil, width: int(rect.size.width), height: int(rect.size.height), bitspercomponent: bitspercomponent!, bytesperrow: 0, space: colorspace!, bitmapinfo: (bitmapinfo?.rawvalue)!)
// draw the image in the center of the context, leaving a gap around the edges
let imagelocation = cgrect(x: padding, y: padding, width: image!.size.width, height: image!.size.height)
context?.draw(self.cgimage!, in: imagelocation)
// create a mask to make the border transparent, and combine it with the image
let transparentimage = uiimage(cgimage: (context?.makeimage()?.masking(imageref(withpadding: padding, size: rect.size))!)!)
return transparentimage
}
/**
creates a mask that makes the outer edges transparent and everything else opaque. the size must include the entire mask (opaque part + transparent border).
- parameter padding: the padding amount.
- parameter size: the size of the image.
- returns a core graphics image ref
*/
fileprivate func imageref(withpadding padding: cgfloat, size: cgsize) -> cgimage {
// build a context that's the same dimensions as the new size
let colorspace = cgcolorspacecreatedevicegray()
let bitmapinfo = cgbitmapinfo(rawvalue: cgbitmapinfo().rawvalue | cgimagealphainfo.none.rawvalue)
let context = cgcontext(data: nil, width: int(size.width), height: int(size.height), bitspercomponent: 8, bytesperrow: 0, space: colorspace, bitmapinfo: bitmapinfo.rawvalue)
// start with a mask that's entirely transparent
context?.setfillcolor(uicolor.black.cgcolor)
context?.fill(cgrect(x: 0, y: 0, width: size.width, height: size.height))
// make the inner part (within the border) opaque
context?.setfillcolor(uicolor.white.cgcolor)
context?.fill(cgrect(x: padding, y: padding, width: size.width - padding * 2, height: size.height - padding * 2))
// get an image of the context
let maskimageref = context?.makeimage()
return maskimageref!
}
// mark: crop
/**
creates a cropped copy of an image.
- parameter bounds: the bounds of the rectangle inside the image.
- returns a new image
*/
func crop(bounds: cgrect) -> uiimage? {
return uiimage(cgimage: (self.cgimage?.cropping(to: bounds)!)!,
scale: 0.0, orientation: self.imageorientation)
}
func croptosquare() -> uiimage? {
let size = cgsize(width: self.size.width * self.scale, height: self.size.height * self.scale)
let shortest = min(size.width, size.height)
let left: cgfloat = (size.width > shortest) ? (size.width - shortest) / 2 : 0
let top: cgfloat = (size.height > shortest) ? (size.height - shortest) / 2 : 0
let rect = cgrect(x: 0, y: 0, width: size.width, height: size.height)
let insetrect = rect.insetby(dx: left, dy: top)
return crop(bounds: insetrect)
}
// mark: resize
/**
creates a resized copy of an image.
- parameter size: the new size of the image.
- parameter contentmode: the way to handle the content in the new size.
- returns a new image
*/
func resize(tosize: cgsize, contentmode: uiimagecontentmode = .scaletofill) -> uiimage? {
let horizontalratio = size.width / self.size.width;
let verticalratio = size.height / self.size.height;
var ratio: cgfloat!
switch contentmode {
case .scaletofill:
ratio = 1
case .scaleaspectfill:
ratio = max(horizontalratio, verticalratio)
case .scaleaspectfit:
ratio = min(horizontalratio, verticalratio)
}
let rect = cgrect(x: 0, y: 0, width: size.width * ratio, height: size.height * ratio)
// fix for a colorspace / transparency issue that affects some types of
// images. see here: https://vocaro.com/trevor/blog/2009/10/12/resize-a-uiimage-the-right-way/comment-page-2/#comment-39951
let colorspace = cgcolorspacecreatedevicergb()
let bitmapinfo = cgbitmapinfo(rawvalue: cgimagealphainfo.premultipliedlast.rawvalue)
let context = cgcontext(data: nil, width: int(rect.size.width), height: int(rect.size.height), bitspercomponent: 8, bytesperrow: 0, space: colorspace, bitmapinfo: bitmapinfo.rawvalue)
let transform = cgaffinetransform.identity
// rotate and/or flip the image if required by its orientation
context?.concatenate(transform);
// set the quality level to use when rescaling
context!.interpolationquality = cginterpolationquality(rawvalue: 3)!
//cgcontextsetinterpolationquality(context, cginterpolationquality(kcginterpolationhigh.value))
// draw into the context; this scales the image
context?.draw(self.cgimage!, in: rect)
// get the resized image from the context and a uiimage
let newimage = uiimage(cgimage: (context?.makeimage()!)!, scale: self.scale, orientation: self.imageorientation)
return newimage;
}
// mark: corner radius
/**
creates a new image with rounded corners.
- parameter cornerradius: the corner radius.
- returns a new image
*/
func roundcorners(cornerradius: cgfloat) -> uiimage? {
// if the image does not have an alpha layer, add one
let imagewithalpha = applyalpha()
if imagewithalpha == nil {
return nil
}
uigraphicsbeginimagecontextwithoptions(size, false, 0)
let width = imagewithalpha?.cgimage?.width
let height = imagewithalpha?.cgimage?.height
let bits = imagewithalpha?.cgimage?.bitspercomponent
let colorspace = imagewithalpha?.cgimage?.colorspace
let bitmapinfo = imagewithalpha?.cgimage?.bitmapinfo
let context = cgcontext(data: nil, width: width!, height: height!, bitspercomponent: bits!, bytesperrow: 0, space: colorspace!, bitmapinfo: (bitmapinfo?.rawvalue)!)
let rect = cgrect(x: 0, y: 0, width: cgfloat(width!)*scale, height: cgfloat(height!)*scale)
context?.beginpath()
if (cornerradius == 0) {
context?.addrect(rect)
} else {
context?.savegstate()
context?.translateby(x: rect.minx, y: rect.miny)
context?.scaleby(x: cornerradius, y: cornerradius)
let fw = rect.size.width / cornerradius
let fh = rect.size.height / cornerradius
context?.move(to: cgpoint(x: fw, y: fh/2))
context?.addarc(tangent1end: cgpoint(x: fw, y: fh), tangent2end: cgpoint(x: fw/2, y: fh), radius: 1)
context?.addarc(tangent1end: cgpoint(x: 0, y: fh), tangent2end: cgpoint(x: 0, y: fh/2), radius: 1)
context?.addarc(tangent1end: cgpoint(x: 0, y: 0), tangent2end: cgpoint(x: fw/2, y: 0), radius: 1)
context?.addarc(tangent1end: cgpoint(x: fw, y: 0), tangent2end: cgpoint(x: fw, y: fh/2), radius: 1)
context?.restoregstate()
}
context?.closepath()
context?.clip()
context?.draw(imagewithalpha!.cgimage!, in: rect)
let image = uiimage(cgimage: (context?.makeimage()!)!, scale:scale, orientation: .up)
uigraphicsendimagecontext()
return image
}
/**
creates a new image with rounded corners and border.
- parameter cornerradius: the corner radius.
- parameter border: the size of the border.
- parameter color: the color of the border.
- returns a new image
*/
func roundcorners(cornerradius: cgfloat, border: cgfloat, color: uicolor) -> uiimage? {
return roundcorners(cornerradius: cornerradius)?.apply(border: border, color: color)
}
/**
creates a new circle image.
- returns a new image
*/
func roundcornerstocircle() -> uiimage? {
let shortest = min(size.width, size.height)
return croptosquare()?.roundcorners(cornerradius: shortest/2)
}
/**
creates a new circle image with a border.
- parameter border :cgfloat the size of the border.
- parameter color :uicolor the color of the border.
- returns uiimage?
*/
func roundcornerstocircle(withborder border: cgfloat, color: uicolor) -> uiimage? {
let shortest = min(size.width, size.height)
return croptosquare()?.roundcorners(cornerradius: shortest/2, border: border, color: color)
}
// mark: border
/**
creates a new image with a border.
- parameter border: the size of the border.
- parameter color: the color of the border.
- returns a new image
*/
func apply(border: cgfloat, color: uicolor) -> uiimage? {
uigraphicsbeginimagecontextwithoptions(size, false, 0)
let width = self.cgimage?.width
let height = self.cgimage?.height
let bits = self.cgimage?.bitspercomponent
let colorspace = self.cgimage?.colorspace
let bitmapinfo = self.cgimage?.bitmapinfo
let context = cgcontext(data: nil, width: width!, height: height!, bitspercomponent: bits!, bytesperrow: 0, space: colorspace!, bitmapinfo: (bitmapinfo?.rawvalue)!)
var red: cgfloat = 0, green: cgfloat = 0, blue: cgfloat = 0, alpha: cgfloat = 0
color.getred(&red, green: &green, blue: &blue, alpha: &alpha)
context?.setstrokecolor(red: red, green: green, blue: blue, alpha: alpha)
context?.setlinewidth(border)
let rect = cgrect(x: 0, y: 0, width: size.width*scale, height: size.height*scale)
let inset = rect.insetby(dx: border*scale, dy: border*scale)
context?.strokeellipse(in: inset)
context?.draw(self.cgimage!, in: inset)
let image = uiimage(cgimage: (context?.makeimage()!)!)
uigraphicsendimagecontext()
return image
}
// mark: image effects
/**
applies a light blur effect to the image
- returns new image or nil
*/
func applylighteffect() -> uiimage? {
return applyblur(withradius: 30, tintcolor: uicolor(white: 1.0, alpha: 0.3), saturationdeltafactor: 1.8)
}
/**
applies a extra light blur effect to the image
- returns new image or nil
*/
func applyextralighteffect() -> uiimage? {
return applyblur(withradius: 20, tintcolor: uicolor(white: 0.97, alpha: 0.82), saturationdeltafactor: 1.8)
}
/**
applies a dark blur effect to the image
- returns new image or nil
*/
func applydarkeffect() -> uiimage? {
return applyblur(withradius: 20, tintcolor: uicolor(white: 0.11, alpha: 0.73), saturationdeltafactor: 1.8)
}
/**
applies a color tint to an image
- parameter color: the tint color
- returns new image or nil
*/
func applytinteffect(tintcolor: uicolor) -> uiimage? {
let effectcoloralpha: cgfloat = 0.6
var effectcolor = tintcolor
let componentcount = tintcolor.cgcolor.numberofcomponents
if componentcount == 2 {
var b: cgfloat = 0
if tintcolor.getwhite(&b, alpha: nil) {
effectcolor = uicolor(white: b, alpha: effectcoloralpha)
}
} else {
var red: cgfloat = 0
var green: cgfloat = 0
var blue: cgfloat = 0
if tintcolor.getred(&red, green: &green, blue: &blue, alpha: nil) {
effectcolor = uicolor(red: red, green: green, blue: blue, alpha: effectcoloralpha)
}
}
return applyblur(withradius: 10, tintcolor: effectcolor, saturationdeltafactor: -1.0)
}
/**
applies a blur to an image based on the specified radius, tint color saturation and mask image
- parameter blurradius: the radius of the blur.
- parameter tintcolor: the optional tint color.
- parameter saturationdeltafactor: the detla for saturation.
- parameter maskimage: the optional image for masking.
- returns new image or nil
*/
func applyblur(withradius blurradius: cgfloat, tintcolor: uicolor?, saturationdeltafactor: cgfloat, maskimage: uiimage? = nil) -> uiimage? {
guard size.width > 0 && size.height > 0 && cgimage != nil else {
return nil
}
if maskimage != nil {
guard maskimage?.cgimage != nil else {
return nil
}
}
let imagerect = cgrect(origin: cgpoint.zero, size: size)
var effectimage = self
let hasblur = blurradius > cgfloat(flt_epsilon)
let hassaturationchange = fabs(saturationdeltafactor - 1.0) > cgfloat(flt_epsilon)
if (hasblur || hassaturationchange) {
uigraphicsbeginimagecontextwithoptions(size, false, 0.0)
let effectincontext = uigraphicsgetcurrentcontext()
effectincontext?.scaleby(x: 1.0, y: -1.0)
effectincontext?.translateby(x: 0, y: -size.height)
effectincontext?.draw(cgimage!, in: imagerect)
var effectinbuffer = vimage_buffer(
data: effectincontext?.data,
height: uint((effectincontext?.height)!),
width: uint((effectincontext?.width)!),
rowbytes: (effectincontext?.bytesperrow)!)
uigraphicsbeginimagecontextwithoptions(size, false, 0.0);
let effectoutcontext = uigraphicsgetcurrentcontext()
var effectoutbuffer = vimage_buffer(
data: effectoutcontext?.data,
height: uint((effectoutcontext?.height)!),
width: uint((effectoutcontext?.width)!),
rowbytes: (effectoutcontext?.bytesperrow)!)
if hasblur {
let inputradius = blurradius * uiscreen.main.scale
let sqrtpi: cgfloat = cgfloat(sqrt(m_pi * 2.0))
var radius = uint32(floor(inputradius * 3.0 * sqrtpi / 4.0 + 0.5))
if radius % 2 != 1 {
radius += 1 // force radius to be odd so that the three box-blur methodology works.
}
let imageedgeextendflags = vimage_flags(kvimageedgeextend)
vimageboxconvolve_argb8888(&effectinbuffer, &effectoutbuffer, nil, 0, 0, radius, radius, nil, imageedgeextendflags)
vimageboxconvolve_argb8888(&effectoutbuffer, &effectinbuffer, nil, 0, 0, radius, radius, nil, imageedgeextendflags)
vimageboxconvolve_argb8888(&effectinbuffer, &effectoutbuffer, nil, 0, 0, radius, radius, nil, imageedgeextendflags)
}
var effectimagebuffersareswapped = false
if hassaturationchange {
let s: cgfloat = saturationdeltafactor
let floatingpointsaturationmatrix: [cgfloat] = [
0.0722 + 0.9278 * s, 0.0722 - 0.0722 * s, 0.0722 - 0.0722 * s, 0,
0.7152 - 0.7152 * s, 0.7152 + 0.2848 * s, 0.7152 - 0.7152 * s, 0,
0.2126 - 0.2126 * s, 0.2126 - 0.2126 * s, 0.2126 + 0.7873 * s, 0,
0, 0, 0, 1
]
let pisor: cgfloat = 256
let matrixsize = floatingpointsaturationmatrix.count
var saturationmatrix = [int16](repeating: 0, count: matrixsize)
for i: int in 0 ..< matrixsize {
saturationmatrix[i] = int16(round(floatingpointsaturationmatrix[i] * pisor))
}
if hasblur {
vimagematrixmultiply_argb8888(&effectoutbuffer, &effectinbuffer, saturationmatrix, int32(pisor), nil, nil, vimage_flags(kvimagenoflags))
effectimagebuffersareswapped = true
} else {
vimagematrixmultiply_argb8888(&effectinbuffer, &effectoutbuffer, saturationmatrix, int32(pisor), nil, nil, vimage_flags(kvimagenoflags))
}
}
if !effectimagebuffersareswapped {
effectimage = uigraphicsgetimagefromcurrentimagecontext()!
}
uigraphicsendimagecontext()
if effectimagebuffersareswapped {
effectimage = uigraphicsgetimagefromcurrentimagecontext()!
}
uigraphicsendimagecontext()
}
// set up output context.
uigraphicsbeginimagecontextwithoptions(size, false, uiscreen.main.scale)
let outputcontext = uigraphicsgetcurrentcontext()
outputcontext?.scaleby(x: 1.0, y: -1.0)
outputcontext?.translateby(x: 0, y: -size.height)
// draw base image.
outputcontext?.draw(self.cgimage!, in: imagerect)
// draw effect image.
if hasblur {
outputcontext?.savegstate()
if let image = maskimage {
outputcontext?.clip(to: imagerect, mask: image.cgimage!);
}
outputcontext?.draw(effectimage.cgimage!, in: imagerect)
outputcontext?.restoregstate()
}
// add in color tint.
if let color = tintcolor {
outputcontext?.savegstate()
outputcontext?.setfillcolor(color.cgcolor)
outputcontext?.fill(imagerect)
outputcontext?.restoregstate()
}
// output image is ready.
let outputimage = uigraphicsgetimagefromcurrentimagecontext()
uigraphicsendimagecontext()
return outputimage
}
// mark: image from url
/**
creates a new image from a url with optional caching. if cached, the cached image is returned. otherwise, a place holder is used until the image from web is returned by the closure.
- parameter url: the image url.
- parameter placeholder: the placeholder image.
- parameter shouldcacheimage: weather or not we should cache the nsurl response (default: true)
- parameter closure: returns the image from the web the first time is fetched.
- returns a new image
*/
class func image(fromurl url: string, placeholder: uiimage, shouldcacheimage: bool = true, closure: @escaping (_ image: uiimage?) -> ()) -> uiimage? {
// from cache
if shouldcacheimage {
if let image = uiimage.shared.object(forkey: url as anyobject) as? uiimage {
closure(nil)
return image
}
}
// fetch image
let session = urlsession(configuration: urlsessionconfiguration.default)
if let nsurl = url(string: url) {
session.datatask(with: nsurl, completionhandler: { (data, response, error) -> void in
if (error != nil) {
dispatchqueue.main.async {
closure(nil)
}
}
if let data = data, let image = uiimage(data: data) {
if shouldcacheimage {
uiimage.shared.setobject(image, forkey: url as anyobject)
}
dispatchqueue.main.async {
closure(image)
}
}
session.finishtasksandinvalidate()
}).resume()
}
return placeholder
}
}
import foundation
import uikit
import quartzcore
public extension uiimageview {
/**
loads an image from a url. if cached, the cached image is returned. otherwise, a place holder is used until the image from web is returned by the closure.
- parameter url: the image url.
- parameter placeholder: the placeholder image.
- parameter fadein: weather the mage should fade in.
- parameter closure: returns the image from the web the first time is fetched.
- returns a new image
*/
func imagefromurl(_ url: string, placeholder: uiimage, fadein: bool = true, shouldcacheimage: bool = true, closure: ((_ image: uiimage?) -> ())? = nil)
{
self.image = uiimage.image(fromurl: url, placeholder: placeholder, shouldcacheimage: shouldcacheimage) {
(image: uiimage?) in
if image == nil {
return
}
self.image = image
if fadein {
let transition = catransition()
transition.duration = 0.5
transition.timingfunction = camediatimingfunction(name: kcamediatimingfunctioneaseineaseout)
transition.type = kcatransitionfade
self.layer.add(transition, forkey: nil)
}
closure?(image)
}
}
}
//
// slidergallerycontroller.swift
// hangge_1314
//
// created by hangge on 2018/2/5.
// 图片轮播的controller
//
import uikit
//定义图片轮播组件的接口
protocol slidergallerycontrollerdelegate{
//获取数据源
func gallerydatasource()->[string]
//获取内部scrollerview的宽高尺寸
func galleryscrollerviewsize()->cgsize
}
//图片轮播组件控制器
class slidergallerycontroller: uiviewcontroller,uiscrollviewdelegate{
//接口对象
var delegate : slidergallerycontrollerdelegate!
//屏幕宽度
let kscreenwidth = uiscreen.main.bounds.size.width
//当前展示的图片索引
var currentindex : int = 0
//数据源
var datasource : [string]?
//用于轮播的左中右三个image（不管几张图片都是这三个imageview交替使用）
var leftimageview , middleimageview , rightimageview : uiimageview?
//放置imageview的滚动视图
var scrollerview : uiscrollview?
//scrollview的宽和高
var scrollerviewwidth : cgfloat?
var scrollerviewheight : cgfloat?
//页控制器（小圆点）
var pagecontrol : uipagecontrol?
//加载指示符（用来当iamgeview还没将图片显示出来时，显示的图片）
var placeholderimage:uiimage!
//自动滚动计时器
var autoscrolltimer:timer?
override func viewdidload() {
super.viewdidload()
//获取并设置scrollerview尺寸
let size : cgsize = self.delegate.galleryscrollerviewsize()
self.scrollerviewwidth = size.width
self.scrollerviewheight = size.height
//获取数据
self.datasource = self.delegate.gallerydatasource()
//设置scrollerview
self.configurescrollerview()
//设置加载指示图片
self.configureplaceholder()
//设置imageview
self.configureimageview()
//设置页控制器
self.configurepagecontroller()
//设置自动滚动计时器
self.configureautoscrolltimer()
self.view.backgroundcolor = uicolor.black
}
//设置scrollerview
func configurescrollerview(){
self.scrollerview = uiscrollview(frame: cgrect(x: 0,y: 0,
width: self.scrollerviewwidth!,
height: self.scrollerviewheight!))
self.scrollerview?.backgroundcolor = uicolor.red
self.scrollerview?.delegate = self
self.scrollerview?.contentsize = cgsize(width: self.scrollerviewwidth! * 3,
height: self.scrollerviewheight!)
//滚动视图内容区域向左偏移一个view的宽度
self.scrollerview?.contentoffset = cgpoint(x: self.scrollerviewwidth!, y: 0)
self.scrollerview?.ispagingenabled = true
self.scrollerview?.bounces = false
self.view.addsubview(self.scrollerview!)
}
//设置加载指示图片(图片还未加载出来时显示的)
func configureplaceholder(){
//这里我使用imagehelper将文字转换成图片，作为加载指示符
let font = uifont.systemfont(ofsize: 17.0, weight: uifont.weight.medium)
let size = cgsize(width: self.scrollerviewwidth!, height: self.scrollerviewheight!)
placeholderimage = uiimage(text: "图片加载中...", font:font,
color:uicolor.white, size:size)!
}
//设置imageview
func configureimageview(){
self.leftimageview = uiimageview(frame: cgrect(x: 0, y: 0,
width: self.scrollerviewwidth!,
height: self.scrollerviewheight!))
self.middleimageview = uiimageview(frame: cgrect(x: self.scrollerviewwidth!, y: 0,
width: self.scrollerviewwidth!,
height: self.scrollerviewheight! ))
self.rightimageview = uiimageview(frame: cgrect(x: 2*self.scrollerviewwidth!, y: 0,
width: self.scrollerviewwidth!,
height: self.scrollerviewheight!))
self.scrollerview?.showshorizontalscrollindicator = false
//设置初始时左中右三个imageview的图片（分别时数据源中最后一张，第一张，第二张图片）
if(self.datasource?.count != 0){
resetimageviewsource()
}
self.scrollerview?.addsubview(self.leftimageview!)
self.scrollerview?.addsubview(self.middleimageview!)
self.scrollerview?.addsubview(self.rightimageview!)
}
//设置页控制器
func configurepagecontroller() {
self.pagecontrol = uipagecontrol(frame: cgrect(x: kscreenwidth/2-60,
y: self.scrollerviewheight! - 20, width: 120, height: 20))
self.pagecontrol?.numberofpages = (self.datasource?.count)!
self.pagecontrol?.isuserinteractionenabled = false
self.view.addsubview(self.pagecontrol!)
}
//设置自动滚动计时器
func configureautoscrolltimer() {
//设置一个定时器，每三秒钟滚动一次
autoscrolltimer = timer.scheduledtimer(timeinterval: 3, target: self,
selector: #selector(slidergallerycontroller.letitscroll),
userinfo: nil, repeats: true)
}
//计时器时间一到，滚动一张图片
@objc func letitscroll(){
let offset = cgpoint(x: 2*scrollerviewwidth!, y: 0)
self.scrollerview?.setcontentoffset(offset, animated: true)
}
//每当滚动后重新设置各个imageview的图片
func resetimageviewsource() {
//当前显示的是第一张图片
if self.currentindex == 0 {
self.leftimageview?.imagefromurl(self.datasource!.last!,
placeholder: placeholderimage)
self.middleimageview?.imagefromurl(self.datasource!.first!,
placeholder: placeholderimage)
let rightimageindex = (self.datasource?.count)!>1 ? 1 : 0 //保护
self.rightimageview?.imagefromurl(self.datasource![rightimageindex],
placeholder: placeholderimage)
}
//当前显示的是最好一张图片
else if self.currentindex == (self.datasource?.count)! - 1 {
self.leftimageview?.imagefromurl(self.datasource![self.currentindex-1],
placeholder: placeholderimage)
self.middleimageview?.imagefromurl(self.datasource!.last!,
placeholder: placeholderimage)
self.rightimageview?.imagefromurl(self.datasource!.first!,
placeholder: placeholderimage)
}
//其他情况
else{
self.leftimageview?.imagefromurl(self.datasource![self.currentindex-1],
placeholder: placeholderimage)
self.middleimageview?.imagefromurl(self.datasource![self.currentindex],
placeholder: placeholderimage)
self.rightimageview?.imagefromurl(self.datasource![self.currentindex+1],
placeholder: placeholderimage)
}
}
//scrollview滚动完毕后触发
func scrollviewdidscroll(_ scrollview: uiscrollview) {
//获取当前偏移量
let offset = scrollview.contentoffset.x
if(self.datasource?.count != 0){
//如果向左滑动（显示下一张）
if(offset >= self.scrollerviewwidth!*2){
//还原偏移量
scrollview.contentoffset = cgpoint(x: self.scrollerviewwidth!, y: 0)
//视图索引+1
self.currentindex = self.currentindex + 1
if self.currentindex == self.datasource?.count {
self.currentindex = 0
}
}
//如果向右滑动（显示上一张）
if(offset <= 0){
//还原偏移量
scrollview.contentoffset = cgpoint(x: self.scrollerviewwidth!, y: 0)
//视图索引-1
self.currentindex = self.currentindex - 1
if self.currentindex == -1 {
self.currentindex = (self.datasource?.count)! - 1
}
}
//重新设置各个imageview的图片
resetimageviewsource()
//设置页控制器当前页码
self.pagecontrol?.currentpage = self.currentindex
}
}
//手动拖拽滚动开始
func scrollviewwillbegindragging(_ scrollview: uiscrollview) {
//使自动滚动计时器失效（防止用户手动移动图片的时候这边也在自动滚动）
autoscrolltimer?.invalidate()
}
//手动拖拽滚动结束
func scrollviewdidenddragging(_ scrollview: uiscrollview,
willdecelerate decelerate: bool) {
//重新启动自动滚动计时器
configureautoscrolltimer()
}
//重新加载数据
func reloaddata() {
//索引重置
self.currentindex = 0
//重新获取数据
self.datasource = self.delegate.gallerydatasource()
//页控制器更新
self.pagecontrol?.numberofpages = (self.datasource?.count)!
self.pagecontrol?.currentpage = 0
//重新设置各个imageview的图片
resetimageviewsource()
}
override func didreceivememorywarning() {
super.didreceivememorywarning()
}
}
//
// bannerviewcontroller.swift
// iostest
//
// created by 陕西帮你电子科技有限公司 on 2018/5/4.
// copyright ? 2018年 陕西帮你电子科技有限公司. all rights reserved.
// 实现图片轮播
//
import uikit
import swiftyjson
import alamofire
//实现slidergallerycontrollerdelegate接口
class bannerviewcontroller: uiviewcontroller,slidergallerycontrollerdelegate {
//获取屏幕的宽度
let screenwidth = uiscreen.main.bounds.size.width
//自定义的图片轮播的组件
var slidergallery : slidergallerycontroller!
//图片轮播的数据源(string类型的数组)
var imgagedata = [string]()
override func viewdidload() {
super.viewdidload()
//请求服务获取轮播图片
getimagedata()
}
//图片轮播组件接口获取数据源的方法
func gallerydatasource() -> [string] {
return imgagedata
}
//图片轮播组件接口的方法,获取内部scrollview的尺寸
func galleryscrollerviewsize() -> cgsize {
return cgsize(width: screenwidth-20, height: (screenwidth-20)/4*3)
}
//点击事件响应
@objc func handletapaction(_ tap:uitapgesturerecognizer) -> void {
//获取图片的索引值
let index = slidergallery.currentindex
print("宝宝你点击了\(index)张图片")
}
//初始化轮播组件
func initslidergallery(){
//初始化图片轮播组件
slidergallery = slidergallerycontroller()
//设置 slidergallerycontrollerdelegate 接口的监听事件
slidergallery.delegate = self
slidergallery.view.frame = cgrect(x: 10, y: 40, width: screenwidth-20, height: (screenwidth-20)/4*3)
//将图片轮播组件添加到当前视图
self.addchildviewcontroller(slidergallery)
self.view.addsubview(slidergallery.view)
//添加组件的点击事件
let tap = uitapgesturerecognizer(target: self, action: #selector(bannerviewcontroller.handletapaction(_:)))
slidergallery.view.addgesturerecognizer(tap)
}
//请求服务器获取轮播图片的数据
func getimagedata(){
//获取当前时间
let now = date()
//当前时间的时间戳
let timeinterval:timeinterval = now.timeintervalsince1970
let timestamp = string(timeinterval)
let url = url(string: "https://47.92.107.28:8000/static/banner.f?_=\(timestamp)")!
alamofire.request(url,method: .get,parameters: nil,encoding: urlencoding.default,headers:nil).responsejson { response
in
switch response.result.issuccess {
case true:
if let value = response.result.value{
self.imgagedata = []
//获取返回的值,转为json对象
let img_json = json(value)
//json转字符串
let json_str = img_json.rawstring()
let zhu_url = "https://47.92.107.28:8000"
//遍历json数据
for(key,item) in img_json["imgs"] {
//print("src的值:\(item["src"])")
//如果取得的 src 的值为 string类型的话就添加到数组中
if let img_url = item["src"].string{
//将图片路径添加到数组中
self.imgagedata.append(zhu_url+img_url)
}
}
let str = self.imgagedata.joined()
//print("请求到返回的数据\(json_str)")
//初始化轮播组件
self.initslidergallery()
}
case false:
print(response.result.error)
uialertcontroller.showalert(message: "网络连接失败")
}
}
}
override func didreceivememorywarning() {
super.didreceivememorywarning()
// dispose of any resources that can be recreated.
}
}
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