Source code for visidata.basesheet

import os

import visidata
from visidata import Extensible, VisiData, vd, EscapeException, MissingAttrFormatter, AttrDict


UNLOADED = tuple()  # sentinel for a sheet not yet loaded for the first time

vd.beforeExecHooks = [] # func(sheet, cmd, args, keystrokes) called before the exec()

class LazyChainMap:
    'provides a lazy mapping to obj attributes.  useful when some attributes are expensive properties.'
    def __init__(self, *objs, locals=None):
        self.locals = {} if locals is None else locals
        self.objs = {} # [k] -> obj
        for obj in objs:
            for k in dir(obj):
                if k not in self.objs:
                    self.objs[k] = obj

    def __iter__(self):
        return iter(self.objs)

    def __contains__(self, k):
        return k in self.objs

    def keys(self):
        return list(self.objs.keys())  # sum(set(dir(obj)) for obj in self.objs))

    def get(self, key, default=None):
        if key in self.locals:
            return self.locals[key]
        return self.objs.get(key, default)

    def clear(self):
        self.locals.clear()

    def __getitem__(self, k):
        obj = self.objs.get(k, None)
        if obj:
            return getattr(obj, k)
        return self.locals[k]

    def __setitem__(self, k, v):
        obj = self.objs.get(k, None)
        if obj:
            return setattr(obj, k, v)
        self.locals[k] = v


class DrawablePane(Extensible):
    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)

    'Base class for all interaction owners that can be drawn in a window.'
    def draw(self, scr):
        'Draw on the terminal window *scr*.  Should be overridden.'
        vd.error('no draw')

    @property
    def windowHeight(self):
        'Height of the current sheet window, in terminal lines.'
        return self._scr.getmaxyx()[0] if self._scr else 25

    @property
    def windowWidth(self):
        'Width of the current sheet window, in single-width characters.'
        return self._scr.getmaxyx()[1] if self._scr else 80

    @property
    def currow(self):
        return None

    def execCommand2(self, cmd, vdglobals=None):
        "Execute `cmd` with `vdglobals` as globals and this sheet's attributes as locals.  Return True if user cancelled."

        try:
            self.sheet = self
            code = compile(cmd.execstr, cmd.longname, 'exec')
            exec(code, vdglobals, LazyChainMap(vd, self))
            return False
        except EscapeException as e:  # user aborted
            vd.warning(str(e))
            return True


class _dualproperty:
    'Return *obj_method* or *cls_method* depending on whether property is on instance or class.'
    def __init__(self, obj_method, cls_method):
        self._obj_method = obj_method
        self._cls_method = cls_method

    def __get__(self, obj, objtype=None):
        if obj is None:
            return self._cls_method(objtype)
        else:
            return self._obj_method(obj)


[docs]class BaseSheet(DrawablePane): 'Base class for all sheet types.' _rowtype = object # callable (no parms) that returns new empty item _coltype = None # callable (no parms) that returns new settable view into that item rowtype = 'objects' # one word, plural, describing the items precious = True # False for a few discardable metasheets defer = False # False for not deferring changes until save guide = '' # default to show in sidebar def _obj_options(self): return vd.OptionsObject(vd._options, obj=self) def _class_options(cls): return vd.OptionsObject(vd._options, obj=cls) class_options = options = _dualproperty(_obj_options, _class_options) def __init__(self, *names, rows=UNLOADED, **kwargs): self._name = None # initial cache value necessary for self.options self._names = [] self.loading = False self.names = list(names) self.source = None self.rows = rows # list of opaque objects self._scr = None self.hasBeenModified = False super().__init__(**kwargs) self._sidebar = '' def setModified(self): if not self.hasBeenModified: vd.addUndo(setattr, self, 'hasBeenModified', self.hasBeenModified) self.hasBeenModified = True def __lt__(self, other): if self.name != other.name: return self.name < other.name else: return id(self) < id(other) def __copy__(self): 'Return shallow copy of sheet.' cls = self.__class__ ret = cls.__new__(cls) ret.__dict__.update(self.__dict__) ret.precious = True # copy can be precious even if original is not ret.hasBeenModified = False # copy is not modified even if original is return ret def __bool__(self): 'an instantiated Sheet always tests true' return True def __len__(self): 'Number of elements on this sheet.' return self.nRows def __str__(self): return self.name @property def rows(self): return self._rows @rows.setter def rows(self, rows): self._rows = rows @property def nRows(self): 'Number of rows on this sheet. Override in subclass.' return 0 def __contains__(self, vs): if self.source is vs: return True if isinstance(self.source, BaseSheet): return vs in self.source return False @property def displaySource(self): if isinstance(self.source, BaseSheet): return f'the *{self.source}* sheet' if isinstance(self.source, (list, tuple)): if len(self.source) == 1: return f'the **{self.source[0]}** sheet' return f'{len(self.source)} sheets' return f'**{self.source}**' def execCommand(self, longname, vdglobals=None, keystrokes=None): if ' ' in longname: cmd, arg = longname.split(' ', maxsplit=1) vd.injectInput(arg) cmd = self.getCommand(longname or keystrokes) if not cmd: vd.fail('no command for %s' % (longname or keystrokes)) return False escaped = False err = '' if vdglobals is None: vdglobals = vd.getGlobals() vd.cmdlog # make sure cmdlog has been created for first command try: for hookfunc in vd.beforeExecHooks: hookfunc(self, cmd, '', keystrokes) escaped = super().execCommand2(cmd, vdglobals=vdglobals) except Exception as e: vd.debug(cmd.execstr) err = vd.exceptionCaught(e) escaped = True if vd.cmdlog: # sheet may have changed vd.callNoExceptions(vd.cmdlog.afterExecSheet, vd.activeSheet, escaped, err) vd.callNoExceptions(self.checkCursor) vd.clearCaches() for t in self.currentThreads: if not hasattr(t, 'lastCommand'): t.lastCommand = True return escaped @property def lastCommandThreads(self): return [t for t in self.currentThreads if getattr(t, 'lastCommand', None)] @property def names(self): return self._names @names.setter def names(self, names): if self._names: vd.addUndo(setattr, self, 'names', self._names) self._names = names self._name = self.options.name_joiner.join(self.maybeClean(str(x)) for x in self._names) @property def name(self): 'Name of this sheet.' return self._name @name.setter def name(self, name): 'Set name without spaces.' if self._names: vd.addUndo(setattr, self, 'names', self._names) self._name = self.maybeClean(str(name)) self._names = [self._name] def maybeClean(self, s): 'stub' return s def recalc(self): 'Clear any calculated value caches.' pass def refresh(self): 'Recalculate any internal state needed for `draw()`. Overridable.' pass def ensureLoaded(self): 'Call ``reload()`` if not already loaded.' if self.rows is UNLOADED: self.rows = [] # prevent auto-reload from running twice return self.reload() # likely launches new thread def reload(self): 'Load sheet from *self.source*. Override in subclass.' vd.error('no reload') @property def cursorRow(self): 'The row object at the row cursor. Overridable.' return None def checkCursor(self): 'Check cursor and fix if out-of-bounds. Overridable.' pass def evalExpr(self, expr, **kwargs): 'Evaluate Python expression *expr* in the context of *kwargs* (may vary by sheet type).' return eval(expr, vd.getGlobals(), dict(sheet=self)) def formatString(self, fmt, **kwargs): 'Return formatted string with *sheet* and *vd* accessible to expressions. Missing expressions return empty strings instead of error.' return MissingAttrFormatter().format(fmt, sheet=self, vd=vd, **kwargs)
@VisiData.api def redraw(vd): 'Clear the terminal screen and let the next draw cycle recreate the windows and redraw everything.' for vs in vd.sheets: vs._scr = None if vd.win1: vd.win1.clear() if vd.win2: vd.win2.clear() if vd.scrFull: vd.scrFull.clear() vd.setWindows(vd.scrFull) @VisiData.property def sheet(self): return self.activeSheet @VisiData.api def isLongname(self, ks:str): 'Return True if *ks* is a longname.' return ('-' in ks) and (ks[-1] != '-') or (len(ks) > 3 and ks.islower()) @VisiData.api def getSheet(vd, sheetname): 'Return Sheet from the sheet stack. *sheetname* can be a sheet name or a sheet number indexing directly into ``vd.sheets``.' if isinstance(sheetname, BaseSheet): return sheetname matchingSheets = [x for x in vd.sheets if x.name == sheetname] if matchingSheets: if len(matchingSheets) > 1: vd.warning('more than one sheet named "%s"' % sheetname) return matchingSheets[0] try: sheetidx = int(sheetname) return vd.sheets[sheetidx] except ValueError: pass if sheetname == 'options': vs = vd.globalOptionsSheet vs.reload() vs.vd = vd return vs