73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
// +build appengine
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// Package gae demonstrates draw2d on a Google appengine server.
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package gae
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import (
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"fmt"
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"image"
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"image/png"
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"net/http"
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"gopkg.in/llgcode/draw2d.v1"
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"gopkg.in/llgcode/draw2d.v1/draw2dpdf"
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"gopkg.in/llgcode/draw2d.v1/samples/android"
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"appengine"
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)
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type appError struct {
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Error error
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Message string
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Code int
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}
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type appHandler func(http.ResponseWriter, *http.Request) *appError
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func (fn appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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if e := fn(w, r); e != nil { // e is *appError, not os.Error.
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c := appengine.NewContext(r)
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c.Errorf("%v", e.Error)
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http.Error(w, e.Message, e.Code)
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}
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}
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func init() {
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http.Handle("/pdf", appHandler(pdf))
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http.Handle("/png", appHandler(imgPng))
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}
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func pdf(w http.ResponseWriter, r *http.Request) *appError {
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w.Header().Set("Content-type", "application/pdf")
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// Initialize the graphic context on an pdf document
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dest := draw2dpdf.NewPdf("L", "mm", "A4")
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gc := draw2dpdf.NewGraphicContext(dest)
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// Draw sample
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android.Draw(gc, 65, 0)
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err := dest.Output(w)
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if err != nil {
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return &appError{err, fmt.Sprintf("Can't write: %s", err), 500}
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}
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return nil
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}
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func imgPng(w http.ResponseWriter, r *http.Request) *appError {
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w.Header().Set("Content-type", "image/png")
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// Initialize the graphic context on an RGBA image
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dest := image.NewRGBA(image.Rect(0, 0, 297, 210.0))
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gc := draw2d.NewGraphicContext(dest)
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// Draw sample
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android.Draw(gc, 65, 0)
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err := png.Encode(w, dest)
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if err != nil {
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return &appError{err, fmt.Sprintf("Can't encode: %s", err), 500}
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}
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return nil
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}
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