improve params errors (#2437)

11 files changed, 167 insertions, 117 deletions

diff --git a/electron/src/renderer/assets/js/simulator.js b/electron/src/renderer/assets/js/simulator.js
index 8a0423f3..e751f137 100644
--- a/electron/src/renderer/assets/js/simulator.js
+++ b/electron/src/renderer/assets/js/simulator.js
@@ -54,7 +54,9 @@ export default {
       showNeedlePenetrationPoints: false,
       renderJumps: true,
       showRealisticPreview: false,
-      showCursor: true
+      showCursor: true,
+      error: false,
+      error_message: ""
     }
   },
   watch: {
@@ -543,6 +545,9 @@ export default {
     zoomPage () {
       this.svg.viewbox(this.page_specs.bbox.x, this.page_specs.bbox.y - 50, this.page_specs.bbox.width + 100, this.page_specs.bbox.height + 100)
       this.resizeCursor()
+    },
+    close () {
+      window.close()
     }
   },
   created: function () {
@@ -642,6 +647,19 @@ export default {
       })
 
       this.start()
+    }).catch(error => {
+      this.loading = false
+      if (error.response) {
+        // Stitch plan generation had an error.  Show it to the user.
+        this.error_message = error.response.data.error_message
+      } else if (error.request) {
+        // We sent the request and didn't get a response.
+        this.error_message = "Stitch plan generation failed."
+      } else {
+        // Something weird happened in axios.
+        this.error_message = error.message
+      }
+      this.error = true
     })
   }
 }
diff --git a/electron/src/renderer/assets/style/simulator.css b/electron/src/renderer/assets/style/simulator.css
index e938cbe3..1ce61865 100644
--- a/electron/src/renderer/assets/style/simulator.css
+++ b/electron/src/renderer/assets/style/simulator.css
@@ -26,12 +26,12 @@
   padding: 1rem;
 }
 
-button {
+.controls button {
   color: rgb(0, 51, 153);
   align-items: flex-start;
   text-align: center;
   cursor: default;
-  background: linear-gradient(0deg, rgba(169,169,169,1) 0%, rgba(255,255,255,1) 68%, rgba(227,227,227,1) 100%);
+  background: linear-gradient(0deg, rgba(169, 169, 169, 1) 0%, rgba(255, 255, 255, 1) 68%, rgba(227, 227, 227, 1) 100%);
   box-sizing: border-box;
   padding: 2px 6px 3px;
   border-width: 2px;
diff --git a/electron/src/renderer/components/Simulator.vue b/electron/src/renderer/components/Simulator.vue
index 6d76b133..e2d65ed8 100644
--- a/electron/src/renderer/components/Simulator.vue
+++ b/electron/src/renderer/components/Simulator.vue
@@ -306,6 +306,19 @@
         </div>
       </div>
     </loading>
+    <v-dialog v-model="error" width="auto">
+      <v-card flat>
+        <v-card-title class="pa-4">
+          Error Generating Stitch Plan
+        </v-card-title>
+        <v-card-text>
+          <p style="white-space: pre-wrap;">{{ error_message }}</p>
+        </v-card-text>
+        <v-card-actions class="justify-center">
+          <v-btn color="primary" variant="text" class="dialog-button" @click="close">Close</v-btn>
+        </v-card-actions>
+      </v-card>
+    </v-dialog>
   </div>
 </template>
 
diff --git a/inkstitch.py b/inkstitch.py
index 1dc5a3e3..91a0f18a 100644
--- a/inkstitch.py
+++ b/inkstitch.py
@@ -7,10 +7,11 @@ import pstats
 import logging
 import os
 import sys
-import traceback
 from argparse import ArgumentParser
 from io import StringIO
 
+from lib.exceptions import InkstitchException, format_uncaught_exception
+
 if getattr(sys, 'frozen', None) is None:
     # When running in development mode, we want to use the inkex installed by
     # pip install, not the one bundled with Inkscape which is not new enough.
@@ -28,7 +29,7 @@ from lxml.etree import XMLSyntaxError
 import lib.debug as debug
 from lib import extensions
 from lib.i18n import _
-from lib.utils import restore_stderr, save_stderr, version
+from lib.utils import restore_stderr, save_stderr
 
 # ignore warnings in releases
 if getattr(sys, 'frozen', None):
@@ -90,24 +91,15 @@ else:
         msg += "\n\n"
         msg += _("Try to import the file into Inkscape through 'File > Import...' (Ctrl+I)")
         errormsg(msg)
+    except InkstitchException as exc:
+        errormsg(str(exc))
     except Exception:
-        exception = traceback.format_exc()
+        errormsg(format_uncaught_exception())
+        sys.exit(1)
     finally:
         restore_stderr()
 
         if shapely_errors.tell():
             errormsg(shapely_errors.getvalue())
 
-    if exception:
-        errormsg(_("Ink/Stitch experienced an unexpected error. This means it is a bug in Ink/Stitch.") + "\n")
-        errormsg(_("If you'd like to help please\n"
-                   "- copy the entire error message below\n"
-                   "- save your SVG file and\n"
-                   "- create a new issue at https://github.com/inkstitch/inkstitch/issues") + "\n")
-        errormsg(_("Include the error description and also (if possible) "
-                   "the svg file.") + "\n")
-        errormsg(version.get_inkstitch_version() + "\n")
-        errormsg(exception)
-        sys.exit(1)
-    else:
-        sys.exit(0)
+    sys.exit(0)
diff --git a/lib/api/stitch_plan.py b/lib/api/stitch_plan.py
index c70efd98..5e9a57c1 100644
--- a/lib/api/stitch_plan.py
+++ b/lib/api/stitch_plan.py
@@ -5,9 +5,9 @@
 
 from flask import Blueprint, g, jsonify
 
+from ..exceptions import InkstitchException, format_uncaught_exception
 from ..stitch_plan import stitch_groups_to_stitch_plan
 
-
 stitch_plan = Blueprint('stitch_plan', __name__)
 
 
@@ -16,10 +16,14 @@ def get_stitch_plan():
     if not g.extension.get_elements():
         return dict(colors=[], stitch_blocks=[], commands=[])
 
-    metadata = g.extension.get_inkstitch_metadata()
-    collapse_len = metadata['collapse_len_mm']
-    min_stitch_len = metadata['min_stitch_len_mm']
-    patches = g.extension.elements_to_stitch_groups(g.extension.elements)
-    stitch_plan = stitch_groups_to_stitch_plan(patches, collapse_len=collapse_len, min_stitch_len=min_stitch_len)
-
-    return jsonify(stitch_plan)
+    try:
+        metadata = g.extension.get_inkstitch_metadata()
+        collapse_len = metadata['collapse_len_mm']
+        min_stitch_len = metadata['min_stitch_len_mm']
+        patches = g.extension.elements_to_stitch_groups(g.extension.elements)
+        stitch_plan = stitch_groups_to_stitch_plan(patches, collapse_len=collapse_len, min_stitch_len=min_stitch_len)
+        return jsonify(stitch_plan)
+    except InkstitchException as exc:
+        return jsonify({"error_message": str(exc)}), 500
+    except Exception:
+        return jsonify({"error_message": format_uncaught_exception()}), 500
diff --git a/lib/elements/element.py b/lib/elements/element.py
index 43cbc8a2..963653af 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -3,6 +3,7 @@
 # Copyright (c) 2010 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
 import sys
+from contextlib import contextmanager
 from copy import deepcopy
 
 import inkex
@@ -11,6 +12,7 @@ from inkex import bezier
 
 from ..commands import find_commands
 from ..debug import debug
+from ..exceptions import InkstitchException, format_uncaught_exception
 from ..i18n import _
 from ..marker import get_marker_elements_cache_key_data
 from ..patterns import apply_patterns, get_patterns_cache_key_data
@@ -546,23 +548,25 @@ class EmbroideryElement(object):
 
     def embroider(self, last_stitch_group):
         debug.log(f"starting {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}")
-        if last_stitch_group:
-            previous_stitch = last_stitch_group.stitches[-1]
-        else:
-            previous_stitch = None
-        stitch_groups = self._load_cached_stitch_groups(previous_stitch)
 
-        if not stitch_groups:
-            self.validate()
+        with self.handle_unexpected_exceptions():
+            if last_stitch_group:
+                previous_stitch = last_stitch_group.stitches[-1]
+            else:
+                previous_stitch = None
+            stitch_groups = self._load_cached_stitch_groups(previous_stitch)
+
+            if not stitch_groups:
+                self.validate()
 
-            stitch_groups = self.to_stitch_groups(last_stitch_group)
-            apply_patterns(stitch_groups, self.node)
+                stitch_groups = self.to_stitch_groups(last_stitch_group)
+                apply_patterns(stitch_groups, self.node)
 
-            if stitch_groups:
-                stitch_groups[-1].trim_after = self.has_command("trim") or self.trim_after
-                stitch_groups[-1].stop_after = self.has_command("stop") or self.stop_after
+                if stitch_groups:
+                    stitch_groups[-1].trim_after = self.has_command("trim") or self.trim_after
+                    stitch_groups[-1].stop_after = self.has_command("stop") or self.stop_after
 
-            self._save_cached_stitch_groups(stitch_groups, previous_stitch)
+                self._save_cached_stitch_groups(stitch_groups, previous_stitch)
 
         debug.log(f"ending {self.node.get('id')} {self.node.get(INKSCAPE_LABEL)}")
         return stitch_groups
@@ -575,14 +579,27 @@ class EmbroideryElement(object):
         else:
             name = id
 
-        # L10N used when showing an error message to the user such as
-        # "Failed on PathLabel (path1234): Satin column: One or more of the rungs doesn't intersect both rails."
-        error_msg = "%s %s: %s" % (_("Failed on "), name, message)
+        error_msg = f"{name}: {message}"
         if point_to_troubleshoot:
             error_msg += "\n\n%s" % _("Please run Extensions > Ink/Stitch > Troubleshoot > Troubleshoot objects. "
-                                      "This will indicate the errorneus position.")
-        inkex.errormsg(error_msg)
-        sys.exit(1)
+                                      "This will show you the exact location of the problem.")
+
+        raise InkstitchException(error_msg)
+
+    @contextmanager
+    def handle_unexpected_exceptions(self):
+        try:
+            # This runs the code in the `with` body so that we can catch
+            # exceptions.
+            yield
+        except (InkstitchException, SystemExit, KeyboardInterrupt):
+            raise
+        except Exception:
+            if hasattr(sys, 'gettrace') and sys.gettrace():
+                # if we're debugging, let the exception bubble up
+                raise
+
+            raise InkstitchException(format_uncaught_exception())
 
     def validation_errors(self):
         """Return a list of errors with this Element.
diff --git a/lib/elements/fill_stitch.py b/lib/elements/fill_stitch.py
index b93d7ff5..c7c3c640 100644
--- a/lib/elements/fill_stitch.py
+++ b/lib/elements/fill_stitch.py
@@ -6,8 +6,6 @@
 import logging
 import math
 import re
-import sys
-import traceback
 
 import numpy as np
 from inkex import Transform
@@ -25,9 +23,8 @@ from ..stitches.meander_fill import meander_fill
 from ..svg import PIXELS_PER_MM, get_node_transform
 from ..svg.clip import get_clip_path
 from ..svg.tags import INKSCAPE_LABEL
-from ..utils import cache, version
+from ..utils import cache
 from ..utils.param import ParamOption
-from ..utils.threading import ExitThread
 from .element import EmbroideryElement, param
 from .validation import ValidationError, ValidationWarning
 
@@ -706,30 +703,25 @@ class FillStitch(EmbroideryElement):
 
             for shape in self.shape.geoms:
                 start = self.get_starting_point(previous_stitch_group)
-                try:
-                    if self.fill_underlay:
-                        underlay_shapes = self.underlay_shape(shape)
-                        for underlay_shape in underlay_shapes.geoms:
-                            underlay_stitch_groups, start = self.do_underlay(underlay_shape, start)
-                            stitch_groups.extend(underlay_stitch_groups)
-
-                    fill_shapes = self.fill_shape(shape)
-                    for i, fill_shape in enumerate(fill_shapes.geoms):
-                        if self.fill_method == 'contour_fill':
-                            stitch_groups.extend(self.do_contour_fill(fill_shape, previous_stitch_group, start))
-                        elif self.fill_method == 'guided_fill':
-                            stitch_groups.extend(self.do_guided_fill(fill_shape, previous_stitch_group, start, end))
-                        elif self.fill_method == 'meander_fill':
-                            stitch_groups.extend(self.do_meander_fill(fill_shape, shape, i, start, end))
-                        elif self.fill_method == 'circular_fill':
-                            stitch_groups.extend(self.do_circular_fill(fill_shape, previous_stitch_group, start, end))
-                        else:
-                            # auto_fill
-                            stitch_groups.extend(self.do_auto_fill(fill_shape, previous_stitch_group, start, end))
-                except ExitThread:
-                    raise
-                except Exception:
-                    self.fatal_fill_error()
+                if self.fill_underlay:
+                    underlay_shapes = self.underlay_shape(shape)
+                    for underlay_shape in underlay_shapes.geoms:
+                        underlay_stitch_groups, start = self.do_underlay(underlay_shape, start)
+                        stitch_groups.extend(underlay_stitch_groups)
+
+                fill_shapes = self.fill_shape(shape)
+                for i, fill_shape in enumerate(fill_shapes.geoms):
+                    if self.fill_method == 'contour_fill':
+                        stitch_groups.extend(self.do_contour_fill(fill_shape, previous_stitch_group, start))
+                    elif self.fill_method == 'guided_fill':
+                        stitch_groups.extend(self.do_guided_fill(fill_shape, previous_stitch_group, start, end))
+                    elif self.fill_method == 'meander_fill':
+                        stitch_groups.extend(self.do_meander_fill(fill_shape, shape, i, start, end))
+                    elif self.fill_method == 'circular_fill':
+                        stitch_groups.extend(self.do_circular_fill(fill_shape, previous_stitch_group, start, end))
+                    else:
+                        # auto_fill
+                        stitch_groups.extend(self.do_auto_fill(fill_shape, previous_stitch_group, start, end))
                 previous_stitch_group = stitch_groups[-1]
 
             return stitch_groups
@@ -885,28 +877,6 @@ class FillStitch(EmbroideryElement):
         else:
             return guide_lines['stroke'][0]
 
-    def fatal_fill_error(self):
-        if hasattr(sys, 'gettrace') and sys.gettrace():
-            # if we're debugging, let the exception bubble up
-            raise
-
-        # for an uncaught exception, give a little more info so that they can create a bug report
-        message = ""
-        message += _("Error during autofill! This means it is a bug in Ink/Stitch.")
-        message += "\n\n"
-        # L10N this message is followed by a URL: https://github.com/inkstitch/inkstitch/issues/new
-        message += _("If you'd like to help please\n"
-                     "- copy the entire error message below\n"
-                     "- save your SVG file and\n"
-                     "- create a new issue at")
-        message += " https://github.com/inkstitch/inkstitch/issues/new\n\n"
-        message += _("Include the error description and also (if possible) the svg file.")
-        message += '\n\n\n'
-        message += version.get_inkstitch_version() + '\n'
-        message += traceback.format_exc()
-
-        self.fatal(message)
-
     def do_circular_fill(self, shape, last_patch, starting_point, ending_point):
         # get target position
         command = self.get_command('ripple_target')
diff --git a/lib/exceptions.py b/lib/exceptions.py
index a9820ac3..3a6b456c 100644
--- a/lib/exceptions.py
+++ b/lib/exceptions.py
@@ -2,6 +2,36 @@
 #
 # Copyright (c) 2010 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+import traceback
+
 
 class InkstitchException(Exception):
     pass
+
+
+def format_uncaught_exception():
+    """Format the current exception as a request for a bug report.
+
+    Call this inside an except block so that there is an exception that we can
+    call traceback.format_exc() on.
+    """
+
+    # importing locally to avoid any possibility of circular import
+    from lib.utils import version
+    from .i18n import _
+
+    message = ""
+    message += _("Ink/Stitch experienced an unexpected error. This means it is a bug in Ink/Stitch.")
+    message += "\n\n"
+    # L10N this message is followed by a URL: https://github.com/inkstitch/inkstitch/issues/new
+    message += _("If you'd like to help please\n"
+                 "- copy the entire error message below\n"
+                 "- save your SVG file and\n"
+                 "- create a new issue at")
+    message += " https://github.com/inkstitch/inkstitch/issues/new\n\n"
+    message += _("Include the error description and also (if possible) the svg file.")
+    message += '\n\n\n'
+    message += version.get_inkstitch_version() + '\n'
+    message += traceback.format_exc()
+
+    return message
diff --git a/lib/extensions/params.py b/lib/extensions/params.py
index 540cc7bb..1ba144b2 100644
--- a/lib/extensions/params.py
+++ b/lib/extensions/params.py
@@ -7,7 +7,6 @@
 
 import os
 import sys
-import traceback
 from collections import defaultdict
 from copy import copy
 from itertools import groupby, zip_longest
@@ -20,6 +19,7 @@ from ..commands import is_command, is_command_symbol
 from ..elements import (Clone, EmbroideryElement, FillStitch, Polyline,
                         SatinColumn, Stroke)
 from ..elements.clone import is_clone
+from ..exceptions import InkstitchException, format_uncaught_exception
 from ..gui import PresetsPanel, SimulatorPreview, WarningPanel
 from ..i18n import _
 from ..svg.tags import SVG_POLYLINE_TAG
@@ -544,24 +544,22 @@ class SettingsFrame(wx.Frame):
                 patches.extend(copy(node).embroider(None))
 
                 check_stop_flag()
-        except SystemExit:
-            wx.CallAfter(self._show_warning)
+        except (SystemExit, ExitThread):
             raise
-        except ExitThread:
-            raise
-        except Exception as e:
-            # Ignore errors.  This can be things like incorrect paths for
-            # satins or division by zero caused by incorrect param values.
-            traceback.print_exception(e, file=sys.stderr)
-            pass
+        except InkstitchException as exc:
+            wx.CallAfter(self._show_warning, str(exc))
+        except Exception:
+            wx.CallAfter(self._show_warning, format_uncaught_exception())
 
         return patches
 
     def _hide_warning(self):
+        self.warning_panel.clear()
         self.warning_panel.Hide()
         self.Layout()
 
-    def _show_warning(self):
+    def _show_warning(self, warning_text):
+        self.warning_panel.set_warning_text(warning_text)
         self.warning_panel.Show()
         self.Layout()
 
diff --git a/lib/gui/warnings.py b/lib/gui/warnings.py
index 48788652..eda1ca2e 100644
--- a/lib/gui/warnings.py
+++ b/lib/gui/warnings.py
@@ -15,14 +15,25 @@ class WarningPanel(wx.Panel):
     def __init__(self, parent, *args, **kwargs):
         wx.Panel.__init__(self, parent, wx.ID_ANY, *args, **kwargs)
 
-        self.warning_box = wx.StaticBox(self, wx.ID_ANY)
+        self.main_sizer = wx.BoxSizer(wx.VERTICAL)
 
         self.warning = wx.StaticText(self)
-        self.warning.SetLabel(_("Cannot load simulator.\nClose Params to get full error message."))
+        self.warning.SetLabel(_("An error occurred while rendering the stitch plan:"))
         self.warning.SetForegroundColour(wx.Colour(255, 25, 25))
+        self.main_sizer.Add(self.warning, 1, wx.LEFT | wx.BOTTOM | wx.EXPAND, 10)
 
-        warning_sizer = wx.StaticBoxSizer(self.warning_box, wx.HORIZONTAL)
-        warning_sizer.Add(self.warning, 1, wx.LEFT | wx.BOTTOM | wx.EXPAND, 10)
+        tc_style = wx.TE_MULTILINE | wx.TE_READONLY | wx.VSCROLL | wx.TE_RICH2
+        self.warning_text = wx.TextCtrl(self, size=(300, 100), style=tc_style)
+        font = self.warning_text.GetFont()
+        font.SetFamily(wx.FONTFAMILY_TELETYPE)
+        self.warning_text.SetFont(font)
+        self.main_sizer.Add(self.warning_text, 3, wx.LEFT | wx.BOTTOM | wx.EXPAND, 10)
 
-        self.SetSizerAndFit(warning_sizer)
+        self.SetSizerAndFit(self.main_sizer)
         self.Layout()
+
+    def set_warning_text(self, text):
+        self.warning_text.SetValue(text)
+
+    def clear(self):
+        self.warning_text.SetValue("")
diff --git a/lib/stitches/meander_fill.py b/lib/stitches/meander_fill.py
index f6106606..c1308bf4 100644
--- a/lib/stitches/meander_fill.py
+++ b/lib/stitches/meander_fill.py
@@ -1,7 +1,6 @@
 from itertools import combinations
 
 import networkx as nx
-from inkex import errormsg
 from shapely.geometry import LineString, MultiPoint, Point
 from shapely.ops import nearest_points
 
@@ -30,10 +29,8 @@ def meander_fill(fill, shape, original_shape, shape_index, starting_point, endin
     graph = tile.to_graph(shape, fill.meander_scale, fill.meander_angle)
 
     if not graph:
-        label = fill.node.label or fill.node.get_id()
-        errormsg(_('%s: Could not build graph for meander stitching. Try to enlarge your shape or '
-                 'scale your meander pattern down.') % label)
-        return []
+        fill.fatal(_('Could not build graph for meander stitching. Try to enlarge your shape or '
+                     'scale your meander pattern down.'))
 
     debug.log_graph(graph, 'Meander graph')
     ensure_connected(graph)