![wxpython imageviewer wxpython imageviewer](https://codingshiksha.com/wp-content/uploads/2021/03/Screenshot_1339.png)
Why this is necessary was explained to me by "you just have to". Note that for this to work we must have set self.SetBackgroundStyle(wx.BG_STYLE_CUSTOM) dc = wx.AutoBufferedPaintDC(self)ĭc.DrawText(self.files, 5, 5) Then, as a bonus, we add some text to the display. Then we clear it and draw the bitmap into the device at the given starting x and y coordinates. The new image is not displayed until it is ready. That is a simple-minded way of looking at double buffering. Now imagine that while you are looking at one image the artist is busy rendering the next (he's really fast) so that when you flip to the next page it is already rendered. Imagine that every time you flipped to a new page you had to wait for the artist to draw the image. When you flip the pages you see an animated scene. You've all seen the flip-style animation where you draw a separate picture on the sheets of a book. I'm either going to insult your intelligence, or expose my ignorance (based on my limited understanding). I'm going to use an analogy to explain what double buffering is.
![wxpython imageviewer wxpython imageviewer](https://user-images.githubusercontent.com/13696193/49056144-6381bc00-f1c8-11e8-9f44-199394823369.jpg)
You can only create a device context within the event handler for an EVT_PAINT event which we will trigger manually by calling the Refresh() method. Consider it like a printer driver, but for the screen. We are going to create something called a device context.
#Wxpython imageviewer how to
For now, let's see how to do a direct draw. Normally you let wxPython handle refreshing the display but in our case we are going to force a redraw on several events. Now comes the part I still find confusing - direct draw using double buffering. Return image.Scale(int(nw*self.zoom), int(nh*self.zoom)) # Determine new size with aspect and adjust if any cropping # Get image size, container size, and calculate aspect ratio """Scale an image to fit parent control""" Note that this only creates a scaled image. If so we recalculate the new width and height based on the container height. Nw,nh the new width and height adjusting for the containerĪfter we calculate the new width and height based on the width of the container we then check to see if the new height is bigger than the container height. cw,ch the height and width of the containerĪspect the aspect ratio h/w of the original image We'll handle the second by using a method called double buffering to do the redrawing of the display. We'll handle the first problem by writing a rescale method to ensure that the image will fit in the container with no distortion. You will usually get an annoying flicker when changing files.The image will be distorted unless the container has the same aspect ratio as the image.There are a few problems with this approach. Convert the image to a bitmap and copy to the wx.StaticBitmap.Scale the image to fit the size of the display control.Read the data from the file into a wx.Image object.Normally, if you wanted to display an image you would use a wx.StaticBitmap control. The images are displayed in one of two modes, windowed, or full-screen. There's a reason I don't get paid to do this. I likely glossed over some things that may need further explanation. I'll check this thread periodically for questions. perCeivedType.py (Utility method for file screening).
#Wxpython imageviewer mod
![wxpython imageviewer wxpython imageviewer](https://raw.githubusercontent.com/PySimpleGUI/PySimpleGUI/master/images/for_readme/TextUpdate.jpg)
I will not get into how to write an app in wxPython. This short tutorial will explain how the pieces work. One of my most often used apps was a shell extension I wrote to add a folder right-click option to launch a small image viewer. That meant rewriting all my VB apps in Python/wxPython.
#Wxpython imageviewer install
Since I haven't used VB.Net in years (nothing but Python now) I did not install Visual Studio.