78e7ae5145
DearMQL5 is an institutional-grade, immediate-mode graphical user interface
(GUI) engine designed from the ground up for MetaTrader 5 (MQL5), inspired by
the ergonomics and performance of Dear ImGui.
### Core Architecture & Execution Pipeline
- Immediate-Mode Paradigm: Declarative frame-based rendering pipeline with zero
memory allocation churn during render loops and deterministic execution.
- Modular Per-Hub Canvas Surfaces (CUWindowSurface): Replaces full-screen canvas
overlays with isolated, window-bounded CCanvas bitmaps, reducing memory usage
by up to 93% (~570 KB vs 8.3 MB for 1080p) and preventing click-swallowing.
- 0-Cost Hardware Texture Drag Engine: Absolute-anchor drag mechanics update
native MT5 OBJPROP_XDISTANCE and OBJPROP_YDISTANCE properties directly on
the compositor, bypassing CPU rasterization completely (0.00% CPU usage).
- Chart Scroll Protection: Automatically suppresses chart history sliding
(CHART_MOUSE_SCROLL) during active HUD dragging and safely restores it on release.
- Two-Phase Hit-Testing: Interactive controls (buttons, sliders, toggles) receive
first-priority click focus, cleanly separating widget actions from window drags.
### Subsystems & Components
- Core State & Input (Core/):
* UInputState: Mouse/keyboard tracking, deltas, and chart scroll lock.
* UState: Retained state hash map in pure MQL5 with 64-bit FNV-1a hashing.
* UIdStack: Hierarchical identifier scoping preventing widget ID collisions.
* ULayout: Automatic cursor placement supporting SameLine, Indent, and Unindent.
* UEventQueue: Non-blocking circular UI event queue for decoupled handling.
* UTheme: Institutional OneDark/Nord dark color palette and typography metrics.
- Rendering Backends (Render/):
* URendererCanvas: Isolated per-hub surfaces with 32-bit ARGB alpha transparency.
* URendererNative: Native MT5 object pool (OBJ_RECTANGLE_LABEL) with diff caching.
* UFont: Anti-aliased font metrics and width cache.
- Complete Widget Suite (Widgets/):
* UButton: Click-on-release standard, accent, and emergency panic buttons.
* UToggle: Smooth draggable/clickable iOS-style toggle switches.
* USlider: Draggable horizontal float and integer sliders.
* UProgressBar: Adaptive progress bars with dynamic green->amber->red color ramps.
* UHeader: Collapsible section headers with immediate-mode state retention.
* ULabel & USeparator: Formatted text, colored metrics, and horizontal dividers.
- Window Management (Windows/):
* UWindow: Window container with titlebar, collapse toggle, and coordinate clipping.
* UWindowManager: Multi-window coordinator with GlobalVariable persistence across
chart timeframe changes and backward-compatible key resolution.
### Tooling, Documentation & Reference Implementation
- Examples/EA_DearMQL5_Demo.mq5: Complete reference Prop-Firm cockpit HUD.
- README.md: Comprehensive institutional English documentation for GitHub and Algo Forge.
- Docs/ARCHITECTURE.md: Technical architecture specification with Mermaid lifecycle.
44 lines
1.5 KiB
MQL5
44 lines
1.5 KiB
MQL5
//+------------------------------------------------------------------+
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//| USlider.mqh |
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//| Copyright 2026, DearMQL5 GUI Engine |
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//| https://www.mql5.com |
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//+------------------------------------------------------------------+
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#property copyright "Copyright 2026, DearMQL5 GUI Engine"
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#property link "https://www.mql5.com"
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#property strict
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#include "UWidget.mqh"
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#include "..\Render\UFont.mqh"
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#include "..\Util\UMath.mqh"
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/// Horizontal draggable slider for numeric parameter adjustment.
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class USlider
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{
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public:
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/// Computes slider dimensions including trailing label.
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static void GetBoundingBox(const string label, const int custom_w,
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int &out_w, int &out_h)
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{
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SUTheme th = UTheme::Get();
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out_w = (custom_w > 0) ? custom_w : ULayout::GetAvailableWidth();
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out_h = th.widget_height;
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}
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/// Updates slider value based on mouse dragging position across the track.
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static bool ProcessDrag(const int x, const int w,
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const double min_val, const double max_val,
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double &io_val)
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{
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int mx = UInputState::MouseX();
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double fraction = (double)(mx - x) / (double)w;
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fraction = UMath::Clamp(fraction, 0.0, 1.0);
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double new_val = min_val + fraction * (max_val - min_val);
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if(new_val != io_val)
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{
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io_val = new_val;
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return(true);
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}
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return(false);
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}
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};
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