maemo.org - Talk - Maemo5 & PyQT4 - Implementing an image-viewer.

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Maemo5 & PyQT4 - Implementing an image-viewer.

I am working on developing a comic/image viewer frontend for an application I'm designing.

Now, what I'd like to end up with is similar to the built-in image viewer(at least, the actual "show image" part), but with some differences.

I'm looking at:
1. Displaying an image with some text below it. Currently I'm using QTextBrowser, which seems to do the job.
2. Scaling of both text and image. I just need to be able to either set a % or get the current width and be able to set a pixel #.
2.5. Relatedly, I need to figure out how to get button presses of the zoom/volume keys.
3. Having portrait mode support(at least manually, through a setting).
4. Being able to slide your finger on the touchscreen to switch between images(Like how the built-in viewer does it).
5. long-press/right-click menu for whatever I end up using as my image/text viewer. How can I set this up?
6. Some sort of "multi-page" interface, like the image-viewer: You can click the "back" button in the upper right-hand corner to view another page(in that case, a list of images). In my case, it will be a QTreeWidget object.

Can you guys point me to some pages, tutorials and or code-snippets that might help me with these things?

Thanks,

-RobbieThe1st

Re: Maemo5 & PyQT4 - Implementing an image-viewer.

woah, lots of questions :) - i'm by no means an authority on anything pyqt but here goes!

1) Text Browser (Opening an HTML File, so it could assist in opening an image if you want!)

Code:

self.textBrowser = QtGui.QTextBrowser(self.tab_4)

self.textBrowser.setGeometry(QtCore.QRect(0, 10, 781, 301))

self.textBrowser.setOpenExternalLinks(True)

fsock = os.popen('cat /home/opt/healthcheck/about.txt').read()

self.textBrowser.setHtml(fsock)

# self.textBrowser.setText (fsock)

# Make the font small!!!

font = QtGui.QFont()

font.setPointSize(20)

2. Scaling of both text and image. - May i ask scaling dependent on what? As scaling normally depends on something changing... - the above example shows the font size being set/changed.
But i assume you mean auto-rotate style repositioning. What you would need to do is to read the width and height and compare it to the current max width or height (800*420 without top bar)
Another way, is to have a slide in menu like the new firefox 4 example- that way whats on your screen can stay it's normal size? :)

2.5. Relatedly, I need to figure out how to get button presses of the zoom/volume keys.
I think 1up in the repos is pyqt and uses these keys - http://maemo.org/downloads/product/Maemo5/1up/ - if it is, might be worth downloading the code and taking a look :)
My assumption, but i dont know how to map the hw keys, sorry!

3. Having portrait mode support(at least manually, through a setting).
This relates to number two! - http://forums.internettablettalk.com...t=31940&page=3 - should help!

4. No idea, sorry! Well kinda, the healthcheck code reads in and detects screen location, if you can use that to detect movements of a specific type it should work :)

Code:

def mouseMoveEvent(self, event):

        self.mousePressPos = QtCore.QPoint(event.pos())

        if self.mousePressPos.isNull():

            event.ignore()

            return

        self.x = self.mousePressPos.x()

        self.y = self.mousePressPos.y()

        event.accept()

        self.update()

5. I think what you mean is a context menu? - as far as i am aware you set up a menu the same as you would for the title/top menu but just call it differently?
http://www.riverbankcomputing.co.uk/...tml/qmenu.html

Code:

import sys

from PyQt4.QtCore import Qt

from PyQt4.QtGui import *



class TableWidget(QTableWidget):



    def __init__(self, parent = None):



        QTableWidget.__init__(self, parent)



    def contextMenuEvent(self, event):



        menu = QMenu(self)

        quitAction = menu.addAction("Quit")

        action = menu.exec_(self.mapToGlobal(event.pos()))

        if action == quitAction:

            qApp.quit()



app = QApplication([])

tableWidget = TableWidget()

tableWidget.show()

sys.exit(app.exec_())

Look here for more info though - http://diotavelli.net/PyQtWiki/Handl...ontext%20menus )

6. Check the healthcheck pages for multipage stuff, the tools page tools stuff mainly load up in new windows.

Sorry typed it all a bit quick, as heading out! hope that helps! :)

Re: Maemo5 & PyQT4 - Implementing an image-viewer.

@noobmonkey:
Thanks.

1. Yea, I have QTextBrowser code working, but I'm not sure it will let me do what I want(especially #2).
2. Thing is, some comics and images look fine scaled down to the resolution of the screen. Some don't.
I intend to have an back-end option that will allow the user to select between scrolling(full-size) and scaled to the screen-size.
Making it match the width, that's easily done. Its getting access to a function that allows me to scale the image onscreen to whatever dimensions I choose that's the issue. More importantly, I need to be able to scale the image [i]using a good[/url] scaling algorithm, just like with the image viewer. Nearest-neighbor etc. just won't do.
Now, last I checked, I could add a pixel-width to the img in the HTML code I'm sending to QTextBrowser, but I'm not sure I could externally change it without reloading the whole code etc. This may be the best option, but I'm really wondering if there's a better widget.

With 3, thanks for that. However, do you know of any -manual- rotation function? I'd like to be able to lock it in portrait mode based on a setting or two.

4. Alright, but there's got to be some sort of library for doing this; it seems kludgy to simply poll the cursor whenever the mouse "button" is down, and then try to extrapolate motion from that.

5. Yes, that's what I mean - I'm just slightly worried about content inside the QTextView(etc) overriding my menu - I'm trying to make the menu appear anywhere, not just where there's no image.

6. Alright, I'll see what I can do...

Re: Maemo5 & PyQT4 - Implementing an image-viewer.

Quote:

Originally Posted by RobbieThe1st (Post 837043)

3) you can set the rotation as you wish using very similar examples.
This one is in python so you can just translate the others (In c++ i think)
self.setAttribute(QtCore.Qt.WA_Maemo5AutoOrientati on, True)

setAttribute(Qt::WA_Maemo5PortraitOrientation, true);
setAttribute(Qt::WA_Maemo5LandscapeOrientation, true);

An example in c .....

Code:

  QRect screenGeometry = QApplication::desktop()->screenGeometry();

         if (screenGeometry.width() > screenGeometry.height())

             label->setText("<p align=\"center\">In Landscape Mode</p>");

         else

             label->setText("<p align=\"center\">In Portrait Mode</p>");

4) Get on IRC - and have a chat with someone like W00t or frals - they should be able to help or point you in the right way :) (Not everyone comes in the forums!)

5) Took me a while to get a normal menu working! I know you can position it depending on where they press , but i have no experience, if you come up with a good example post it for all to see in the wiki! :)
But i'd definitley hunt through the repos for some example python apps that do it already!

As soon as i get a bit of time i'll try and do some proper examples - just got back from hols and back to work monday, so frantically washing, cleaning etc! :P