CRect and CCanvas replacement (Standard Library - several bugs fixed)
This is a powerful addition to your MetaTrader 5 toolkit designed to optimize market analysis and performance. This library provides a collection of modular, reusable code. It is utilized by developers to organize common functions, allowing for the integration of complex logic across multiple Expert Advisors, indicators, or scripts without the need for code duplication.
How to Setup and Use CRect and CCanvas replacement (Standard Library - several bugs fixed)
1. Storage: Place library files in the MQL/Libraries directory to ensure they are accessible to your projects.
2. Implementation: Include the library in your code using the #import directive, ensuring you match the exact function names and parameters.
3. Compilation: Ensure the library is present in the directory before you compile your main EA or script, as the compiler links them during this phase.
4. Management: Keep libraries organized in sub-folders if you manage many custom functions to maintain a clean project structure.
Frequently Asked Questions
Q: What is a library file used for? A: Libraries store reusable code modules, allowing you to centralize common logic used by multiple EAs or indicators.
Q: Is a library executable? A: No, libraries are non-executable files containing functions; they must be imported into an EA, indicator, or script to function.
Q: Can I update a library while the platform is running? A: You should compile your EA or script after updating a library to ensure the latest code changes are integrated.
Description & Settings
MetaQuotes Software, Bugfixes & Enhancements by Doerk.
When you start to work on a pixel basis with the standard library, you'll soon figure out, that sometimes a pixel here and there is missing. This weird behavior is caused mainly by several bugs in the CRect class. The main problem here is, that the original class is failing by calculating the height and the width of a rectangle, which influences almost ALL classes which derive from CWnd, because CWnd is graphically based on CRect.
In the original CRect, the width is calculated as following:
This is simply wrong. When you create any rectangular object starting from 0,0 until 10,10, then the width of the object is 11 pixels, not 10 pixels. Therefore, the right answer is
In some other classes of the standard library it's calculated right, sometimes, but also not always (i.e. in CCanvas when creating and addressing the resource in memory, but not when filling a rectangle). Anyway, it's an inconsistent behavior and should be corrected.
It's now possible to compare two rectangles by using normal operators like == != >= <= > <
instead of coding
you type now just
Furhtermore, unary operators like ++, --, + are supported as well and expand or inflate a rectangle.
Recommendations:
Replace the Rect.mqh by this file in the Controls folder. Don't put it into another folder, it simply won't work.
Replace the Canvas.mqh by the attached file in the Canvas folder. Don't put it into another folder, it won't work.
Make a backup of this file and restore it on new releases of MetaTrader into the original folder.
If MetaQuotes decides to replace the originals by these files, I think you'll be informed anyway.
