parallax/jsPDF

context2d initial property values are not applied

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#3,319 创建于 2021年11月16日

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 (0 评论) (0 反应) (0 负责人)JavaScript (28,280 star) (4,596 fork)batch import
Bugdifficulty:mediumhelp wanted

描述

Example borrowed from #2701:

var doc = new jsPDF()
var ctx = doc.context2d
ctx.strokeText(`font: ${ctx.font}, line: ${ctx.lineWidth}`, 10, 10)
ctx.font = ctx.font // font size is changed(16px → 10px)
ctx.strokeText(`font: ${ctx.font}, line: ${ctx.lineWidth}`, 10, 20)
ctx.lineWidth = ctx.lineWidth // line width is changed(0.2px → 1px)
ctx.strokeText(`font: ${ctx.font}, line: ${ctx.lineWidth}`, 10, 30)

The same thing happens after manually switching or creating pages with addPage or setPage.

A correct solution would probably check if the current document state is the same as the context2d state and if not would apply the properties that are different before executing a command like fill, fillText, stroke, etc.

贡献者指南

技术栈
javascript
领域
frontend
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
JavaScriptjsPDF basics
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
50
研究方向
Investigate the context2d implementation in jsPDF, specifically the initialization of properties like font and lineWidth. The issue highlights that setting a property to its current value changes the value, indicating a state mismatch. Look at the context2d plugin code, likely in files like `src/plugins/context2d.js`, to understand how state is managed. The suggested solution is to compare the current document state with the context2d state before executing drawing commands. Examine methods like `fill`, `stroke`, `fillText`, and `strokeText` to see where to apply this check.