Major update of all demo programs to use new PEP8 bindings, etc

DemoPrograms old/Demo_PDF_Viewer.py

@@ -0,0 +1,187 @@
+"""
+@created: 2018-08-19 18:00:00
+
+@author: (c) 2018 Jorj X. McKie
+
+Display a PyMuPDF Document using Tkinter
+-------------------------------------------------------------------------------
+
+Dependencies:
+-------------
+PyMuPDF, PySimpleGUI > v2.9.0, Tkinter with Tk v8.6+, Python 3
+
+
+License:
+--------
+GNU GPL V3+
+
+Description
+------------
+Read filename from command line and start display with page 1.
+Pages can be directly jumped to, or buttons for paging can be used.
+For experimental / demonstration purposes, we have included options to zoom
+into the four page quadrants (top-left, bottom-right, etc.).
+
+We also interpret keyboard events to support paging by PageDown / PageUp
+keys as if the resp. buttons were clicked. Similarly, we do not include
+a 'Quit' button. Instead, the ESCAPE key can be used, or cancelling the window.
+
+To improve paging performance, we are not directly creating pixmaps from
+pages, but instead from the fitz.DisplayList of the page. A display list
+will be stored in a list and looked up by page number. This way, zooming
+pixmaps and page re-visits will re-use a once-created display list.
+
+"""
+import sys
+import fitz
+if sys.version_info[0] >= 3:
+    import PySimpleGUI as sg
+else:
+    import PySimpleGUI27 as sg
+from sys import exit as exit
+from binascii import hexlify
+
+sg.ChangeLookAndFeel('GreenTan')
+
+if len(sys.argv) == 1:
+    fname = sg.PopupGetFile('PDF Browser', 'PDF file to open', file_types=(("PDF Files", "*.pdf"),))
+    if fname is None:
+        sg.PopupCancel('Cancelling')
+        exit(0)
+else:
+    fname = sys.argv[1]
+
+doc = fitz.open(fname)
+page_count = len(doc)
+
+# storage for page display lists
+dlist_tab = [None] * page_count
+
+title = "PyMuPDF display of '%s', pages: %i" % (fname, page_count)
+
+
+def get_page(pno, zoom=0):
+    """Return a PNG image for a document page number. If zoom is other than 0, one of the 4 page quadrants are zoomed-in instead and the corresponding clip returned.
+
+    """
+    dlist = dlist_tab[pno]  # get display list
+    if not dlist:  # create if not yet there
+        dlist_tab[pno] = doc[pno].getDisplayList()
+        dlist = dlist_tab[pno]
+    r = dlist.rect  # page rectangle
+    mp = r.tl + (r.br - r.tl) * 0.5  # rect middle point
+    mt = r.tl + (r.tr - r.tl) * 0.5  # middle of top edge
+    ml = r.tl + (r.bl - r.tl) * 0.5  # middle of left edge
+    mr = r.tr + (r.br - r.tr) * 0.5  # middle of right egde
+    mb = r.bl + (r.br - r.bl) * 0.5  # middle of bottom edge
+    mat = fitz.Matrix(2, 2)  # zoom matrix
+    if zoom == 1:  # top-left quadrant
+        clip = fitz.Rect(r.tl, mp)
+    elif zoom == 4:  # bot-right quadrant
+        clip = fitz.Rect(mp, r.br)
+    elif zoom == 2:  # top-right
+        clip = fitz.Rect(mt, mr)
+    elif zoom == 3:  # bot-left
+        clip = fitz.Rect(ml, mb)
+    if zoom == 0:  # total page
+        pix = dlist.getPixmap(alpha=False)
+    else:
+        pix = dlist.getPixmap(alpha=False, matrix=mat, clip=clip)
+    return pix.getPNGData()  # return the PNG image
+
+
+window = sg.Window(title, return_keyboard_events=True, use_default_focus=False)
+
+cur_page = 0
+data = get_page(cur_page)  # show page 1 for start
+image_elem = sg.Image(data=data)
+goto = sg.InputText(str(cur_page + 1), size=(5, 1), do_not_clear=True)
+
+layout = [
+    [
+        sg.Button('Prev'),
+        sg.Button('Next'),
+        sg.Text('Page:'),
+        goto,
+    ],
+    [
+        sg.Text("Zoom:"),
+        sg.Button('Top-L'),
+        sg.Button('Top-R'),
+        sg.Button('Bot-L'),
+        sg.Button('Bot-R'),
+    ],
+    [image_elem],
+]
+
+window.Layout(layout)
+my_keys = ("Next", "Next:34", "Prev", "Prior:33", "Top-L", "Top-R",
+           "Bot-L", "Bot-R", "MouseWheel:Down", "MouseWheel:Up")
+zoom_buttons = ("Top-L", "Top-R", "Bot-L", "Bot-R")
+
+old_page = 0
+old_zoom = 0  # used for zoom on/off
+# the zoom buttons work in on/off mode.
+
+while True:
+    event, values = window.Read(timeout=100)
+    zoom = 0
+    force_page = False
+    if event is None:
+        break
+
+    if event in ("Escape:27",):  # this spares me a 'Quit' button!
+        break
+    # print("hex(button)", hexlify(button.encode()))
+    if event[0] == chr(13):  # surprise: this is 'Enter'!
+        try:
+            cur_page = int(values[0]) - 1  # check if valid
+            while cur_page < 0:
+                cur_page += page_count
+        except:
+            cur_page = 0  # this guy's trying to fool me
+        goto.Update(str(cur_page + 1))
+        # goto.TKStringVar.set(str(cur_page + 1))
+
+    elif event in ("Next", "Next:34", "MouseWheel:Down"):
+        cur_page += 1
+    elif event in ("Prev", "Prior:33", "MouseWheel:Up"):
+        cur_page -= 1
+    elif event == "Top-L":
+        zoom = 1
+    elif event == "Top-R":
+        zoom = 2
+    elif event == "Bot-L":
+        zoom = 3
+    elif event == "Bot-R":
+        zoom = 4
+
+    # sanitize page number
+    if cur_page >= page_count:  # wrap around
+        cur_page = 0
+    while cur_page < 0:  # we show conventional page numbers
+        cur_page += page_count
+
+    # prevent creating same data again
+    if cur_page != old_page:
+        zoom = old_zoom = 0
+        force_page = True
+
+    if event in zoom_buttons:
+        if 0 < zoom == old_zoom:
+            zoom = 0
+            force_page = True
+
+        if zoom != old_zoom:
+            force_page = True
+
+    if force_page:
+        data = get_page(cur_page, zoom)
+        image_elem.Update(data=data)
+        old_page = cur_page
+    old_zoom = zoom
+
+    # update page number field
+    if event in my_keys or not values[0]:
+        goto.Update(str(cur_page + 1))
+        # goto.TKStringVar.set(str(cur_page + 1))