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PyBrowser: a nicer QTextBrowser

2004-02-02 18:09

Work­ing on some of my per­son­al projects (specif­i­cal­ly KRsN and Not­ty), I have need­ed to make QTextBrows­er act a lit­tle more like a men­sch in a few ways:

  • Since it un­der­stands a lot of HTM­L, why not make it open im­ages ref­er­enced in the tex­t, and fol­low links?
  • Since it can show what is pret­ty much a web page, why not make it use HTTP and what­ev­er as need­ed?
  • Make it print. The helpview­er ex­am­ple has all the need­ed code. So, I stole it.

To achieve these goal­s, I had to dig in­to QMime­Source­Fac­to­ry and QDragOb­jec­t, and it ain't all that pret­ty :-)

Click here for the python file (it's in the pub­lic do­main, do as you wish with it).

Cur­rent prob­lem­s:

  • Slow
  • Very slow
  • Does­n't give close to enough feed­back
  • Should have a cache (it's triv­ial)

If any­one who has bet­ter python kung­fu can help me, I'm a hap­py guy.

The re­sult, in 143 lines of python, count­ing blanks and lit­tle de­mo prog­gie is this:

Source code for pybrowser.py
from qt import *
import urlparse
import traceback
from urllib import urlopen
import time


class  Mime­Fac­to­ry(QMimeSourceFactory):

        current=None

        def  __init__(self,browser):
                QMimeSourceFactory.__init__(self)
                self.browser=browser

        def  da­ta(self,name,context=None):
                if context:
                        return self.data(self.makeAbsolute(name,context))
                res=None
                (local,type,subtype)=self.fetchURL(str(name))
                if type=="image":
                        i=QImage()
                        #If image loading fails, return empty image
                        if not i.loadFromData(local,None):
                                i.create(10,10,8)
                        res=QImageDrag(i)
                else: #Assume it's text
                        res=QTextDrag(local)
                        if subtype=="html":
                                res.setSubtype("html")
                        else:
                                res.setSubtype("plain")
                self.current=res
                return self.current

        def  make­Ab­so­lute(self,name,context):
                return urlparse.urljoin(str(context),str(name))

        def  fetchURL(self,url):
                local=""
                type="text"
                subtype="plain"
                try:
                        remote=urlopen(url)
                        info=remote.info()
                        (type,subtype)=info.gettype().split("/")
                        local=remote.read()
                        l=info.getheader('content-length')
                        if not l:
                                l=0
                        else:
                                l=int(l)
                        print 'size',l

                        p=0
                        c=0
                        bsize=1024
                        while True:
                                self.browser.emit(PYSIGNAL('status'),("Downloading: "\
+url+"(%sKB)"%str(p/1024),))
                                self.browser.emit(PYSIGNAL('size'),(p,))
                                if l:
                                        self.browser.emit(PYSIGNAL('percent'),((p*100)/l,))
                                qApp.processEvents()
                                #Lame attempt at making this report about once a second
                                stamp=time.time()
                                c=c+1
                                buf=remote.read(int(bsize))
                                delta=time.time()-stamp
                                if delta <.5: #Data coming quickly, get more on each loop
                                        bsize=min(bsize*1.25,10000)
                                elif delta >.75: #Data coming slowly, get less on each loop
                                        bsize=max(bsize*.75,100)

                                #End of file
                                if buf=='':
                                        self.browser.emit(PYSIGNAL('percent'),(100,))
                                        break

                                p=p+len(buf)
                                local=local+buf

                except:
                        traceback.print_exc()
                return (local,type,subtype)

        def  print­Page(self):
                printer=QPrinter(QPrinter.HighResolution)
                printer.setFullPage(True)
                if printer.setup(self):
                        p=QPainter(printer)
                        if not p.isActive(): # starting printing failed
                                return;
                        metrics=QPaintDeviceMetrics(p.device())
                        dpiy = metrics.logicalDpiY()
                        margin = int(((2/2.54)*dpiy)) # 2 cm margins
                        body=QRect(margin, margin, metrics.width() - 2*margin,
                                        metrics.height()-2*margin)
                        richText=QSimpleRichText( self.viewer.text(),
                                                        QFont(),
                                                        self.viewer.context(),
                                                        self.viewer.styleSheet(),
                                                        self.viewer.mimeSourceFactory(),
                                                        body.height() )
                        richText.setWidth( p, body.width() )
                        view=QRect(body)
                        page = 1
                        while True:
                                richText.draw(p,body.left(),body.top(),view,self.colorGroup())
                                view.moveBy(0,body.height())
                                p.translate(0,-body.height())
                                p.drawText(view.right()-p.fontMetrics().width(str(page)),
                                                view.bottom()+p.fontMetrics().ascent()+5,
                                                str(page));
                                if view.top()  >= richText.height():
                                        break
                                printer.newPage()
                                page+=1
                        p.end()


class  QBrows­er(QTextBrowser):
        def  __init__(self,parent=None):
                QTextBrowser.__init__(self,parent)
                self.mf=MimeFactory(self)
                self.setMimeSourceFactory(self.mf)

def  print­it(arg):
        print str(arg)

if __name__=="__main__":
        from sys import argv
        app=QApplication(argv)
        w=QBrowser()

        w.connect(w,PYSIGNAL('percent'),printit)
        w.connect(w,PYSIGNAL('size'),printit)
        w.connect(w,PYSIGNAL('status'),printit)

        w.show()
        w.setSource(argv[1])
        app.connect(app, SIGNAL("lastWindowClosed()")
                                , app, SLOT("quit()"))
        app.exec_loop()
murdoch ravlin / 2007-03-25 17:53:

the
def printPage(self):

does nothing just delete it.

Roberto Alsina / 2007-03-25 19:13:

What do you mean it does nothing? I haven't looked at this code in three years or so, but I'm pretty sure it did something back then :-)

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