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authorTerry Jan Reedy <tjreedy@udel.edu>2016-05-22 23:10:31 (GMT)
committerTerry Jan Reedy <tjreedy@udel.edu>2016-05-22 23:10:31 (GMT)
commit0d9220e162f1e5f8caa3d7ebaa54665776d361a1 (patch)
treea4fa9f7cafdfc93fde86b8ffd6088d739bb93e01 /Lib/idlelib/codecontext.py
parentdc4f7c09cc934524a763498250e30123a0d9d2c5 (diff)
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Issue #24225: Rename many idlelib/*.py and idlelib/idle_test/test_*.py files.
Diffstat (limited to 'Lib/idlelib/codecontext.py')
-rw-r--r--Lib/idlelib/codecontext.py176
1 files changed, 176 insertions, 0 deletions
diff --git a/Lib/idlelib/codecontext.py b/Lib/idlelib/codecontext.py
new file mode 100644
index 0000000..7d25ada
--- /dev/null
+++ b/Lib/idlelib/codecontext.py
@@ -0,0 +1,176 @@
+"""CodeContext - Extension to display the block context above the edit window
+
+Once code has scrolled off the top of a window, it can be difficult to
+determine which block you are in. This extension implements a pane at the top
+of each IDLE edit window which provides block structure hints. These hints are
+the lines which contain the block opening keywords, e.g. 'if', for the
+enclosing block. The number of hint lines is determined by the numlines
+variable in the CodeContext section of config-extensions.def. Lines which do
+not open blocks are not shown in the context hints pane.
+
+"""
+import tkinter
+from tkinter.constants import TOP, LEFT, X, W, SUNKEN
+import re
+from sys import maxsize as INFINITY
+from idlelib.configHandler import idleConf
+
+BLOCKOPENERS = {"class", "def", "elif", "else", "except", "finally", "for",
+ "if", "try", "while", "with"}
+UPDATEINTERVAL = 100 # millisec
+FONTUPDATEINTERVAL = 1000 # millisec
+
+getspacesfirstword =\
+ lambda s, c=re.compile(r"^(\s*)(\w*)"): c.match(s).groups()
+
+class CodeContext:
+ menudefs = [('options', [('!Code Conte_xt', '<<toggle-code-context>>')])]
+ context_depth = idleConf.GetOption("extensions", "CodeContext",
+ "numlines", type="int", default=3)
+ bgcolor = idleConf.GetOption("extensions", "CodeContext",
+ "bgcolor", type="str", default="LightGray")
+ fgcolor = idleConf.GetOption("extensions", "CodeContext",
+ "fgcolor", type="str", default="Black")
+ def __init__(self, editwin):
+ self.editwin = editwin
+ self.text = editwin.text
+ self.textfont = self.text["font"]
+ self.label = None
+ # self.info is a list of (line number, indent level, line text, block
+ # keyword) tuples providing the block structure associated with
+ # self.topvisible (the linenumber of the line displayed at the top of
+ # the edit window). self.info[0] is initialized as a 'dummy' line which
+ # starts the toplevel 'block' of the module.
+ self.info = [(0, -1, "", False)]
+ self.topvisible = 1
+ visible = idleConf.GetOption("extensions", "CodeContext",
+ "visible", type="bool", default=False)
+ if visible:
+ self.toggle_code_context_event()
+ self.editwin.setvar('<<toggle-code-context>>', True)
+ # Start two update cycles, one for context lines, one for font changes.
+ self.text.after(UPDATEINTERVAL, self.timer_event)
+ self.text.after(FONTUPDATEINTERVAL, self.font_timer_event)
+
+ def toggle_code_context_event(self, event=None):
+ if not self.label:
+ # Calculate the border width and horizontal padding required to
+ # align the context with the text in the main Text widget.
+ #
+ # All values are passed through getint(), since some
+ # values may be pixel objects, which can't simply be added to ints.
+ widgets = self.editwin.text, self.editwin.text_frame
+ # Calculate the required vertical padding
+ padx = 0
+ for widget in widgets:
+ padx += widget.tk.getint(widget.pack_info()['padx'])
+ padx += widget.tk.getint(widget.cget('padx'))
+ # Calculate the required border width
+ border = 0
+ for widget in widgets:
+ border += widget.tk.getint(widget.cget('border'))
+ self.label = tkinter.Label(self.editwin.top,
+ text="\n" * (self.context_depth - 1),
+ anchor=W, justify=LEFT,
+ font=self.textfont,
+ bg=self.bgcolor, fg=self.fgcolor,
+ width=1, #don't request more than we get
+ padx=padx, border=border,
+ relief=SUNKEN)
+ # Pack the label widget before and above the text_frame widget,
+ # thus ensuring that it will appear directly above text_frame
+ self.label.pack(side=TOP, fill=X, expand=False,
+ before=self.editwin.text_frame)
+ else:
+ self.label.destroy()
+ self.label = None
+ idleConf.SetOption("extensions", "CodeContext", "visible",
+ str(self.label is not None))
+ idleConf.SaveUserCfgFiles()
+
+ def get_line_info(self, linenum):
+ """Get the line indent value, text, and any block start keyword
+
+ If the line does not start a block, the keyword value is False.
+ The indentation of empty lines (or comment lines) is INFINITY.
+
+ """
+ text = self.text.get("%d.0" % linenum, "%d.end" % linenum)
+ spaces, firstword = getspacesfirstword(text)
+ opener = firstword in BLOCKOPENERS and firstword
+ if len(text) == len(spaces) or text[len(spaces)] == '#':
+ indent = INFINITY
+ else:
+ indent = len(spaces)
+ return indent, text, opener
+
+ def get_context(self, new_topvisible, stopline=1, stopindent=0):
+ """Get context lines, starting at new_topvisible and working backwards.
+
+ Stop when stopline or stopindent is reached. Return a tuple of context
+ data and the indent level at the top of the region inspected.
+
+ """
+ assert stopline > 0
+ lines = []
+ # The indentation level we are currently in:
+ lastindent = INFINITY
+ # For a line to be interesting, it must begin with a block opening
+ # keyword, and have less indentation than lastindent.
+ for linenum in range(new_topvisible, stopline-1, -1):
+ indent, text, opener = self.get_line_info(linenum)
+ if indent < lastindent:
+ lastindent = indent
+ if opener in ("else", "elif"):
+ # We also show the if statement
+ lastindent += 1
+ if opener and linenum < new_topvisible and indent >= stopindent:
+ lines.append((linenum, indent, text, opener))
+ if lastindent <= stopindent:
+ break
+ lines.reverse()
+ return lines, lastindent
+
+ def update_code_context(self):
+ """Update context information and lines visible in the context pane.
+
+ """
+ new_topvisible = int(self.text.index("@0,0").split('.')[0])
+ if self.topvisible == new_topvisible: # haven't scrolled
+ return
+ if self.topvisible < new_topvisible: # scroll down
+ lines, lastindent = self.get_context(new_topvisible,
+ self.topvisible)
+ # retain only context info applicable to the region
+ # between topvisible and new_topvisible:
+ while self.info[-1][1] >= lastindent:
+ del self.info[-1]
+ elif self.topvisible > new_topvisible: # scroll up
+ stopindent = self.info[-1][1] + 1
+ # retain only context info associated
+ # with lines above new_topvisible:
+ while self.info[-1][0] >= new_topvisible:
+ stopindent = self.info[-1][1]
+ del self.info[-1]
+ lines, lastindent = self.get_context(new_topvisible,
+ self.info[-1][0]+1,
+ stopindent)
+ self.info.extend(lines)
+ self.topvisible = new_topvisible
+ # empty lines in context pane:
+ context_strings = [""] * max(0, self.context_depth - len(self.info))
+ # followed by the context hint lines:
+ context_strings += [x[2] for x in self.info[-self.context_depth:]]
+ self.label["text"] = '\n'.join(context_strings)
+
+ def timer_event(self):
+ if self.label:
+ self.update_code_context()
+ self.text.after(UPDATEINTERVAL, self.timer_event)
+
+ def font_timer_event(self):
+ newtextfont = self.text["font"]
+ if self.label and newtextfont != self.textfont:
+ self.textfont = newtextfont
+ self.label["font"] = self.textfont
+ self.text.after(FONTUPDATEINTERVAL, self.font_timer_event)