Shapes: Bugs and TODOs

[letsfindaway]

I use this issue to collect bugs and things to do for the integration of shapes.

Bugs

• Transparent fill colors in a regular and non-regular polygon shape are darker than the marker color, the color in the preview image or the color after conversion to a stroke. Other shapes are not affected.
• Touching a shape with the eraser sometimes removes the filling or the outline completely. I cannot reproduce this issue, but it happens.
• When duplicating a shape with Ctrl+C/Ctrl+V and then terminating OpenBoard, an already deleted item remains in the set of items to be deleted. Happens also when a shape is replaced by a strokes group. I think the mechanism of keeping items in the set mItemsToDelete is some poor architecture. Items should always have some owner responsible for them, even if they are currently not on the scene. See also [Refactor] Ownership of graphic items #248.
• The shape() function for circles and ellipses seems to be broken. We can neither select them nor delete them with the eraser. Only selection with rubber band works. Interestingly it works after saving and reloading a document - sometimes.
• Sometimes a shape moves when clicking with the eraser on it. This happens especially for circles, but also an ellipse seems to move a little bit.
• The fill color for an open polyline is sometimes drawn and sometimes not. What is the intended behavior?
• A line is very hard to select because shape() just returns the path without the width of the pen.
• An Undo action is already created when clicking on a shape. Undoing it will move the shape. UBBoardView calls commitUndoStep() without first starting it. Consider using mWidgetMoved.
• When UBShapeFactory removes an item, e.g. because somebody just clicked without dragging, then the item is removed from the scene, but not deleted.
• When clicking on another tool in the stylus palette after selecting a shapes tool, the shapes tool still remains selected, because it is not part of the action group for stylus tools.
• Keep z Level when substituting stroke by shape (eraser and line at ruler)
• The active area of an open polygon includes the fill area. The user would assume that it is just the line.
• The active area of shapes with transparent filling should be the line only and not the area.
• No visible cursor while creating shape.

TODOs

• Add "Duplicate" action to delegate frame.
• Add z-level handling including delegate buttons.
• Remove delegate frame in edit mode
• Make the outline lines and handles in edit mode always with pen width 2 or 3.
• Make drawing a shape an undoable operation.
• Make editing a shape an undoable operation.
• Make changing the style an undoable operation.
• Move default position of style palette to top center.
• Create a submenu for the Line stylus tool and add the icons to draw the shapes.
• For regular polygons, just provide a single button, e.g. with a pentagon and the letter "n" in it. After drawing this shape, a handle appears in the center. By dragging this handle up and down you can add or remove vertices from the shape.
• Snap behavior for shapes #245
• When moving symmetrical shapes (circle, ellipse, square, rectangle, regular polygon) draw a cross at the center to allow visual adjustment of the position.
• All outlines should have round caps and joins.
• Create a separate function painterPath() returning just the path of an item without the width of the pen. Separate usages of shape() and painterPath(). The function could be a pure virtual function at UBAbstractGraphicsItem and then be implemented by the concrete derived classes.
• Close the shape style palette when pen or marker are selected.
• After drawing a line near the edge of a ruler, convert it to a shape.
• Improve selection of shape items.
• Long click on item for edit mode instead of toggling between two modes. See [Feature] Add Sankore drawing tool #240 (comment). Note: there is already an action associated with a long click of selector or play: If long pressed outside of an item, these tools switch.
• Provide some means to resize a circle by stretching from center. I think this is a common use case. Could also be extended to ellipse, square, rectangle and regular polygon. We could e.g. add a handle at the top right which does this.

[letsfindaway]

Bugs found while testing

• Draw an open polygon. Edit it and make it larger. Use the eraser to remove parts of it. Undo both operations. In some cases remainders of the larger polygons remain on the screen. They vanish if I move e.g. the eraser over this area or even if I deactivate the application by clicking on some other application on my second screen. It seems that some repainting is missing after removing the larger polygon during the undo operation. This is not always reproducible! I added prepareGeometryChange() to UBAbstractGraphicsItem::copyItemParameters(). After that, I could no longer observe this issue. Closing for now.
• The polygon is the only shape where clicking once activates edit mode. Sometimes, the delegate frame is shortly displayed, but not always.
• After dragging around an unselected polygon, it ends selected and with delegate frame. Probably related to the previous issue.
• Most shapes do not cleanly terminate edit mode when clicking outside. After clicki9ng them a second time, a combined mode with handles and delegate frame is displayed. After a third click we are again on edit. the fourth takes us to selection mode and then everything is again in sync. also a click outside as the fourth fixes this. Only polygons terminate edit mode correctly.
• Directly moving a shape (not with the delegate frame) is not undoable.
• Do not serialize a fill color for open polygons.
• When a shape is part of a group, I can still edit it using the Play tool. However the group frame size does not adapt to this change. Should we adapt the group size or should we disable editing a shape with the Play tool?
• Changing the style of shapes within a group is inconsistent. When we select the group by clicking, we cannot apply a style, as the shapes are not "selected", only the group. When we select a group using the lasso it seems, that sometimes also some of the items in the group are selected. Applying a style applies it to that subset. What do we expect?

[letsfindaway]

More ideas

• If we could enable to edit a text field which is part of a group then we could create groups of shapes and text field, so that we can have some text in shapes. For such groups I would like to couple the size of the text field to the size of the shape, so that the text is always within the shape. The alternative is to allow to apply a style to a text box. But this would then just create rectangles, while the group would also allow to have a circle with text etc.Problem: How can both, the shape and the text field be editable while they are part of a group?
• Should we add a "No Pen" line style to enable drawing shapes consisting only of the fill color? If yes, then we need a mechanism to avoid drawing a shape with no pen and transparent filling. The result would be invisible and unselectable.