Add a sane label type..smh

piker/ui/_label.py

@@ -0,0 +1,188 @@
+# piker: trading gear for hackers
+# Copyright (C) Tyler Goodlet (in stewardship for piker0)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""
+Non-shitty labels that don't re-invent the wheel.
+
+"""
+from typing import Callable
+
+import pyqtgraph as pg
+from PyQt5 import QtGui
+from PyQt5.QtCore import QPointF, QRectF
+
+
+from ._style import (
+    DpiAwareFont,
+    hcolor,
+    _down_2_font_inches_we_like,
+)
+
+
+def vbr_left(label) -> float:
+
+    def viewbox_left():
+        return label.vbr().left()
+
+    return viewbox_left
+
+
+def right_axis(chart, label) -> float:
+    raxis = chart.getAxis('right')
+
+    def right_axis_offset_by_w():
+        return raxis.pos().x() - label.w
+
+    return right_axis_offset_by_w
+
+
+class Label:
+    """
+    After hacking for many days on multiple "label" systems inside
+    ``pyqtgraph`` yet again we're left writing our own since it seems
+    all of those are over complicated, ad-hoc, pieces of garbage that
+    can't accomplish the simplest things, such as pinning to the left
+    hand side of a view box.
+
+    This type is another effort (see our graphics lol) to start making
+    small, re-usable label components that can actually be used to build
+    production grade UIs.
+
+    just.. smh, hard.
+
+    """
+    def __init__(
+        self,
+        view: pg.ViewBox,
+        fmt_str: str,
+        color: str = 'bracket',
+        x_offset: float = 0,
+        font_size_inches: float = _down_2_font_inches_we_like,
+        opacity: float = 0.666,
+        fields: dict = {}
+
+    ) -> None:
+
+        vb = self.vb = view
+        self._fmt_str = fmt_str
+        self._view_xy = QPointF(0, 0)
+
+        self._x_offset = x_offset
+
+        txt = self.txt = QtGui.QGraphicsTextItem()
+        vb.scene().addItem(txt)
+
+        # configure font size based on DPI
+        dpi_font = DpiAwareFont(
+            size_in_inches=font_size_inches
+        )
+        dpi_font.configure_to_dpi()
+        txt.setFont(dpi_font.font)
+
+        txt.setOpacity(opacity)
+
+        # register viewbox callbacks
+        vb.sigRangeChanged.connect(self.on_sigrange_change)
+
+        self._hcolor: str = ''
+        self.color = color
+
+        self.fields = fields
+        self.orient_v = 'bottom'
+
+        self._af = self.txt.pos().x
+
+        # TODO: edit and selection support
+        # https://doc.qt.io/qt-5/qt.html#TextInteractionFlag-enum
+        # self.setTextInteractionFlags(QtGui.Qt.TextEditorInteraction)
+
+    @property
+    def color(self):
+        return self._hcolor
+
+    @color.setter
+    def color(self, color: str) -> None:
+        self.txt.setDefaultTextColor(pg.mkColor(hcolor(color)))
+        self._hcolor = color
+
+    def on_sigrange_change(self, vr, r) -> None:
+        self.set_view_y(self._view_xy.y())
+
+    @property
+    def w(self) -> float:
+        return self.txt.boundingRect().width()
+
+    @property
+    def h(self) -> float:
+        return self.txt.boundingRect().height()
+
+    def vbr(self) -> QRectF:
+        return self.vb.boundingRect()
+
+    def set_x_anchor_func(
+        self,
+        func: Callable,
+    ) -> None:
+        assert isinstance(func(), float)
+        self._af = func
+
+    def set_view_y(
+        self,
+        y: float,
+    ) -> None:
+
+        scene_x = self._af() or self.txt.pos().x()
+
+        # get new (inside the) view coordinates / position
+        self._view_xy = QPointF(
+            self.vb.mapToView(QPointF(scene_x, scene_x)).x(),
+            y,
+        )
+
+        # map back to the outer UI-land "scene" coordinates
+        s_xy = self.vb.mapFromView(self._view_xy)
+
+        if self.orient_v == 'top':
+            s_xy = QPointF(s_xy.x(), s_xy.y() - self.h)
+
+        # move label in scene coords to desired position
+        self.txt.setPos(s_xy)
+
+        assert s_xy == self.txt.pos()
+
+    def orient_on(self, h: str, v: str) -> None:
+        pass
+
+    @property
+    def fmt_str(self) -> str:
+        return self._fmt_str
+
+    @fmt_str.setter
+    def fmt_str(self, fmt_str: str) -> None:
+        self._fmt_str = fmt_str
+
+    def format(self, **fields: dict) -> str:
+        text = self._fmt_str.format(**fields)
+        self.txt.setPlainText(text)
+
+    def render(self) -> None:
+        self.format(**self.fields)
+
+    def show(self) -> None:
+        self.txt.show()
+
+    def hide(self) -> None:
+        self.txt.hide()