MT4 expert trade panel - "OBJ_RECTANGLE_LABEL"

Question

MetaTrader4 Expert Advisor for Trade Panel.
How can I link some OBJ_RECTANGLE_LABEL for moving with another single object?

Answer 1

Link 'em indirectly

There is no direct support for linking a few GUI-objects to move with another one.

This does not mean, it is not possible to have it working like this.

In one Augmented Trader UI-tool, I needed to have both all the GUI-components and some computed values behaving under some similar logic ( keeping all the lines, rectangles, text labels and heat-map colors, under some common UI-control-logic ). All the live-interactive-GUI orchestration was locked onto a few permited user-machine interactions, where the user was able to move with a set of UI-control-objects, some of which were freely modify-able, whereas some were restricted ( with the use of the augmented reality controllers ) to move just vertically or just horizontally or were just locked to start as tangents from the edges of Bollinger Bands in such a place, where the vertical line of the UI-control-object was moved by the user, etc.

The Live-interactive-GUI solution is simple:

Besides the [ Expert Advisor ] create and run another process, the [ Script ] that would be responsible for the GUI-object automation. Within this script, use some read-only values from objects, let's say a blue vertical line, as a SENSOR_x1, an input to the GUI-composition.

If someone or something moves this blue vertical line, your event-watching loop inside the script will detect a new value for the SENSOR_x1
and
re-process all the UI-layout scheme by adding the just observed / detected motion of a SENSOR_x1_delta = SENSOR_x1 - SENSOR_x1_previous;
This way, one can update the motion detector-loop in the [ Script ], chasing all the SENSOR_* actual values and promoting the detected SENSOR_*_delta-s onto all objects, that are being used in the GUI-layout composition.

Finally it is worth to stage the updates of the screen with a few enforced WindowRedraw(); instructions, throughout the re-processing of the augmented reality in the Live-interactive-GUI.

Code from a PoC-demonstrator

One may notice, the code is in a pre-New-MQL4.56789 syntax, using some there permitted variable naming conventions, that ceased to be permitted now. The scope of the Event-Monitor function ( a self-contained function, optimised for max speed / min latency in handling all the three corners of the MVC-framework ( Model-is Live-GUI project-specific, Visual-is the Live-GUI augmentation-specific, Controller-is flexible and composed as a sort of Finite-State-Machine, from principal building blocks and implemented via "object.method" calls in the switch(){}. Loop sampling rate works great down to few tens of milliseconds, so the Live-GUI is robust and smoothly floating on the Trader's Desk.