• Layout of Android (how to realize the layout of hollow circle effect)


    Layer list: in short, layer list means layer list, which is used to create layer drawable. Layer drawable is a kind of drawableresource. Therefore, layer list creates “layer list”, which is a drawable graphic

  • Performance Optimization — moocnet learning notes (first 5 chapters)


    2-2 performance indicators and optimization objectives Come on, what else can we have. 2.2.1 understanding loading waterfall diagram Queuing: you have to queue before you can send it from the browser. DNS loopup: each resource has a domain name. The domain name must be translated into IP, and then the server can be found. Therefore, […]

  • Layer tree and boarding map — IOS Core Animation Series 1


    This series of articles is a series of reading notes. For more information, please see the original text 1. Layer tree 1.1 view A view is a rectangular block (such as a picture, text or video) displayed on the screen, which can intercept user input such as mouse click or touch gesture. Views can be […]

  • Thingjs introduces thermal map technology into 3D visualization field


    IOT data analysis supports the display of equipment distribution and attribute information through thermal map and point aggregation. Thingjs introduces thermal map technology into visualization field, supporting lightweight development! Thermal map is a representation of geographical location visualization, which can make areas with higher than average probability emerge, such as high crime area, high traffic […]

  • WMS service of IOS Gaode Map & mapbox map WMS service


    Web map service (WMS) Web map service (WMS) uses data with geographic location information to make maps. Map is defined as the visual representation of geographic data. It can return the corresponding map according to the user’s request (including PNG, GIF, JPEG and other grid forms, or SVG and web CGM and other vector forms). […]

  • Ideal JavaScript immutable data structure


    1、 Introduction Immer (German for: always) is a tiny package that allows you to work with immutable state in a more convenient way. Immer provides a more convenient way to operate immutable state 2、 Core advantages hisConvenienceIt is mainly reflected in the following aspects: There is only one (core) API:produce(currentState, producer: (draftState) => void): nextState […]

  • [ymfe] how to reach 60fps


    Wang Yu He joined qunar in 2016 and is currently working as a front-end Engineer in the front end architecture group (ymfe) of qunar platform division. Welcome to the team blogYMFE( http://ymfe.tech )See more technologies. Not long ago, I shared some content about building fluent animation on ymfe conf. this article is the text version […]

  • Image processing and composition in JavaScript (2)


    Image processing and composition in JavaScript (2) introduction This series is divided into four parts: Scaling, clipping and rotation of basic image processing technology (portal); Image synthesis of basic type image processing technology; Text synthesis of basic image processing technology; Algorithm type image processing technology; In the last article, we introduced the clipping / rotation […]

  • A kind of Mapbox GL JS learning Exploration Series (4) – solutions for marker overlap


    brief introduction Compared with layer, marker has a more flexible rendering mode, which is suitable for more complex annotation display on the map. At the same time, marker is rendered by Dom and then superimposed on the map layer, so its performance is inferior to layer. In practical application scenarios, when the map needs to […]

  • Implement a simple watermark


    Today, draw a simple watermark with canvas Mount point const watermarkHookElement = document.body; //Get the geometry information of Mount element const rect = watermarkHookElement.getClientRects()[0]; Create canvas const canvas = document.createElement(‘canvas’); canvas.width = rect.width; canvas.height = rect.height; canvas.style.cssText = ‘position: absolute;left: 0;top: 0;z-index: -1;’; watermarkHookElement.appendChild(canvas); Calculate the number of watermarks //Here, 20 and 50 can be […]

  • Baidu heat map, rendering multiple single heat layers with different colors at the same time


    In the project development, product proposal“Increase the thermal distribution of passenger flow sources in this shopping mall and the counterpart shopping malls, and distinguish the thermal power of different shopping malls with a single color”At first glance, it’s a loading method of rendering heat map multiple times at the same time on a map. It’s […]

  • IOS knowledge combing – UI (I) rendering & touch


    Take a look at the IOS UI. There are several important concepts related to IOS UI: window, viewcontroller, view, layer. First of all, we need to know that in these concepts, the core layer of UI presentation, all the information that determines the final presentation is on the layer. View is a direct encapsulation of […]