This patch is adding some code in order to extract a drawing as curves from an image.
The algorithm is basically the following:
- reduce the dimensions
- make it gray
- apply a bilateral filter in order to add some blurryness while keeping the edges
- compute the histogram
- guess what's the background color which should contain a large majority of the pixels
- make a binary image
- extract the contours in using the Suzuki algorithm
- apply the Douglas-Peucker algorithm in order to reduce the number of points
The algorithm is improvable but it should work pretty well if there's a clear difference between
the background and the drawing.
In a v2 we could use a ML model in order to improve the extraction.
There's few changes related to the UI in order to make the tool usable, but they're very basic
for the moment.
This patch fixes a bug that caused incorrect curve shapes when an endpoint lies beyond the page boundaries. It adds a check for the endpoint's position, and if it is outside the page, the point is excluded from the shape's coordinates.
Steps to reproduce this in `master`:
1. Open https://mozilla.github.io/pdf.js/web/viewer.html
2. Use the "Open"-button (in the secondaryToolbar), or drag-and-drop, to load another PDF document.
3. Enable the highlight-editor.
4. Try to pick a new colour.
Note how it's no longer possible to change the default highlight-colour.
The reason for this is that we're only initializing the viewer-toolbar `ColorPicker` *once*, which doesn't work since every PDF document gets its own `AnnotationEditorUIManager`-instance. To address this we simply need to re-initialize the viewer-toolbar `ColorPicker`, and note that this patch won't affect the Firefox PDF Viewer.
It fixes#19239.
When the canvas isn't existing the editor has no image: it's fine because the editor is invisible.
Once it's made visible, the canvas is set when the annotation layer has been rendered.
- it's now possible to start a drawing with a pen and use fingers to zoom
or scroll without interacting with the current drawing;
- it's now possible to draw with a finger and them zoom with two fingers.
When an editor is moved with the keyboard or in dragging it, it is moved in the DOM in order
to make screen readers happy. But this move is slightly postponed thanks to a setTimeout(..., 0).
The failures were very likely due to the fact that intermittently the DOM move was done in
the middle of the next key sequence which was making the move on screen failing.
It was due the resize observer which is removed thanks to this patch.
In order to reuse the dragAndDrop function in test, this patch slighty refactors it
in order to make it easier to use.
When a user deletes any number of annotations, they are notified of the action
by a popup message with an undo button. Besides that, this change reuses the
existing messageBar CSS class from the new alt-text dialog as much as possible.
This patch makes a clear separation between the way to draw and the editing stuff.
It adds a class DrawEditor which should be extended in order to create new drawing tools.
As an example, the ink tool has been rewritten in order to use it.
and tweak a bit the highlight one (e.g. it's useless to have 64 bits floating point numbers
when 32 bits ones are enough).
It's a required step for the refactoring of the ink tool (in order to use the draw layer).
It avoids to call several functions acting on the same SVG element.
The purpose of these changes is to make it more difficult to accidentally include logging statements, used during development and debugging, when submitting patches for review.
For (almost) all code residing in the `src/` folder we should use our existing helper functions to ensure that all logging can be controlled via the `verbosity` API-option.
For the `test/unit/` respectively `test/integration/` folders we shouldn't need any "normal" logging, but it should be OK to print the *occasional* warning/error message.
Please find additional details about the ESLint rule at https://eslint.org/docs/latest/rules/no-console
One goal is to make the code for drawing with the Ink tool similar to the one to free highlighting:
it doesn't really make sense to have so different ways to do almost the same thing.
When the zoom level is high, it'll avoid to create a too big canvas covering all the page which consume
more memory, makes the drawing very slow and the overall user xp pretty bad.
A second goal is to be able to easily implement more drawing tools where we would just have to implement
how to draw from the pointer coordinates.
Currently we manually localize and update the DOM-elements of the AltText-button, and it seems nicer to utilize Fluent "properly" for that task.
This can be achieved by introducing an explicit `span`-element on the AltText-button (similar to e.g. the regular toolbar-buttons), and adding a few more l10n-strings, since that allows just setting the `data-l10n-id`-attribute on all the relevant DOM-elements.
Finally, note how we no longer need to localize any strings eagerly when initializing the various editors.
By using "data-l10n-attrs" it's possible to instruct Fluent to localize *custom* attributes, which means that we don't need to manually translate/update the "default-content" in FreeText editors.
When playing with a pen, I noticed that sometimes a free highlight has still its
gray outline when an other one is drawn: for any reason the pointerleave event isn't
triggered.
It fixes#18849.
When such an annotation is deleted, we make sure that there are some data
to restore.
The version of this patch was making undoing a svg deletion buggy, so it's fixed now and
an integration test has been added for this case.
