- PR #13554 is buggy, so this patch aims to fix bugs.
- check if a component fits into its parent in taking into account the parent layout.
- introduce method isSplittable for template nodes to know if a component can be splitted in case of overflow.
- some containers doesn't always have their 2 dimensions and those dimensions re based on contents;
- so in order to measure text, we must get the glyph widths (for the xfa fonts) before starting the layout;
- implement a word-wrap algorithm;
- handle font change during text layout.
- and fix few bugs:
- avoid infinite loop when layout the document;
- avoid confusion between break and layout failure;
- don't add margin width in tb layout when getting available space.
- it aims to avoid to loop forever when opening pdf in #13213;
- the idea is to consider subformSet as inexistent when running in the tree. So if we've subformA > subformSet > subformB then subformB will be visited as a direct child of subformA.
- attribute 'use' was already implemented but not usehref
- in general, usehref should make reference to current document
- add support for SOM expressions in use and usehref to search a node.
- get prototype for all nodes if any.
- I thought it was possible to rely on browser layout engine to handle layout stuff but it isn't possible
- mainly because when a contentArea overflows, we must continue to layout in the next contentArea
- when no more contentArea is available then we must go to the next page...
- we must handle breakBefore and breakAfter which allows to "break" the layout to go to the next container
- Sometimes some containers don't provide their dimensions so we must compute them in order to know where to put
them in their parents but to compute those dimensions we need to layout the container itself...
- See top of file layout.js for more explanations about layout.
- fix few bugs in other places I met during my work on layout.
- implement few positioning properties: position, width, height, anchor;
- implement font element;
- implement fill element (used by font) and its children (linear, radial, ...);
- font property is inherited from ancestor container (see https://www.pdfa.org/wp-content/uploads/2020/07/XFA-3_3.pdf#page=43) so let CSS handles that stuff;
- in order to reduce the number of properties to set, only set non default properties and put the default in CSS;
- set a background to some containers to be able to see them (will be removed in a future commit).
- add an option to enable XFA rendering if any;
- for now, let the canvas layer: it could be useful to implement XFAF forms (embedded pdf in xml stream for the background and xfa form for the foreground);
- ui elements in template DOM are pretty close to their html counterpart so we generate a fake html DOM from template one:
- it makes easier to translate template properties to html ones;
- it makes faster the creation of the html element in the main thread.
- in order to evaluate SOM expressions nodes and their attributes must be checked in the same order as in the xml;
- add an object XFAObjectArray with a parameter max to handle multiple children with the same name.
- the parser is base on a class extending XMLParserBase
- it handle xml namespaces:
* each namespace is assocated with a builder
* builder builds nodes belonging to the namespace
* when a node is inserted in the parent namespace compatibility is checked (if required)
- to avoid name collision between xml names and object properties, use Symbol.
