Computational notebooks, while essential for data science, are limited by their one-dimensional interface, which poorly aligns with non-linear developer workflows and complicates collaboration and human-AI interaction. In this work, we focus on features of Computational Canvas, a novel two-dimensional interface that evolves notebooks to enhance data analysis and AI-assisted development within integrated development environments (IDEs). We present vital features, including freely arrangeable code cells, separate environments, and improved output management. These features are designed to facilitate intuitive organization, visual exploration, and natural collaboration with other users and AI agents. We also show the implementation of Computational Canvas with designed features as a Visual Studio Code plugin. By shifting from linear to two-dimensional spatial interfaces, we aim to significantly boost developers' productivity in data exploration, experimentation, and AI-assisted development, addressing the current limitations of traditional notebooks and fostering more flexible, collaborative data science workflows.