Thanks for sharing youre work.

But we'll not be able to integrate this as is.
First, you provide only BillMain.php, with new function, but we don't understand when and where this function is called.
Then, you use some "use" syntax, and even if it is good practive, it is not in ProjeQtOr development standards.
But most blocking is the fact that you did not internationalize your messages. You should have used i18n feature.
We cannot understand what is done and what messages mean, because we don't read russian.

We would also need small description of what you wish to do with this new feature...

Thansk in advance for completing your code.

Hi.
in attachment you can find the code I wrote to implement Quotation an Bill creation from project. I must point out that I work on a version namespaced derived from original projeqtor code, so I created the attached code to respond to your request and it has been tested very few. My original idea was just to use it in order to better explain my wishes and I cannot spend more time if you are not interested to introduce these function in ProjeQtor. And my knowledge about ProjeQtor is not enough to be sure that my code fits original ideas on quotation an billing details.
The code you will find in attachment contains
1) code added to
view/objectsButton.php
model/BillMain.php
model/QuotationMain.php
model/BillLine.php
2) code added to
view/js/projeqtor.js
3) added to files
tool/createBill.php
tool/createQuotation.php
4) two lines added to
view/css/common.css
5) Images modified
view/css/customIcons/blue/editorButtonsDisabled.png
view/css/customIcons/blue/editorButtonsEnabled.png
view/css/customIcons/green/editorButtonsDisabled.png
view/css/customIcons/green/editorButtonsEnabled.png
view/css/customIcons/grey/editorButtonsDisabled.png
view/css/customIcons/grey/editorButtonsEnabled.png
view/css/customIcons/red/editorButtonsDisabled.png
view/css/customIcons/red/editorButtonsEnabled.png
6) i18n messages
buttonCreateQuotation: "create a Quotation",
buttonCreateBill: "create a Bill",
projectIdMissing: "Missing project Id",
projectTypeNotBillable: "Cannot create a Bill for this type of project",
validatedAmountAlreadyBilled: "Cannot create a Bill : Validated Amount alreay billed",
termAmountTooBig: "Term amount exceedes billable amount",
noTermForProject: "Cannot create a Bill : No valid term found",
noResourceAffected: "Cannot create a Bill : No resource affected",
noActivityPrice: "Cannot create a Bill : No activity price found for the project",
BillSaved: " Bill saved",
BillSaved: " Bill not saved",
QuotationExisting: "A quotation alredy exists for this project",
projectTypeNotQuotable: "Cannot create a Quotation for this type of project",
QuotationInserted: "Quotation saved",

Unfortunately I cannot speak russian, so I cannot supply messages in other languages ( maybe in italian).

By the way, I could also share my whole namespaced version, but I cannot really believe you are interested in it.
Best regards

Thanks.
We'll have a look and try and integrate it is V6.1