Full mixer implementation — tray, popup, prefs, devices tab with port indicators

Adds the complete tmix feature set built since the initial skeleton:
balance knob, level meters, KLed mute button, system tray with scroll-wheel
volume and recording indicator, tray popup, preferences dialog, right-click
context menus, single-instance enforcement, scroll area, window geometry
persistence, and Devices tab with PA card profile switcher and live port
availability indicators (2-column layout, in-place updates on plug/unplug).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/src/ui/levelmeter.cpp b/src/ui/levelmeter.cpp
new file mode 100644
index 0000000..52412de
--- /dev/null
+++ b/src/ui/levelmeter.cpp
@@ -0,0 +1,67 @@
+#include "levelmeter.h"
+#include <tqpainter.h>
+#include <math.h>
+
+LevelMeter::LevelMeter( TQWidget *parent )
+    : TQWidget(parent), m_level(0.0f)
+{
+    setBackgroundMode( NoBackground );
+}
+
+// Map linear 0..1 amplitude to dB display position 0..1 over a 60dB range.
+// -60dB = bottom, 0dB = top. Matches how real VU meters look.
+static float toDisplayLevel( float linear )
+{
+    if ( linear < 0.001f ) return 0.0f;
+    float db = 20.0f * log10f( linear );  // e.g. 0.3 → -10.5 dB
+    float pos = ( db + 60.0f ) / 60.0f;  // -60..0 dB → 0..1
+    if ( pos < 0.0f ) pos = 0.0f;
+    if ( pos > 1.0f ) pos = 1.0f;
+    return pos;
+}
+
+void LevelMeter::setLevel( float level )
+{
+    if ( level < 0.0f ) level = 0.0f;
+    if ( level > 1.0f ) level = 1.0f;
+
+    float display = toDisplayLevel( level );
+    if ( display > m_level )
+        m_level = m_level * 0.3f + display * 0.7f;  // fast attack, not instant
+    else {
+        m_level *= 0.94f;                            // slow decay ~1.5s to floor
+        if ( m_level < 0.001f ) m_level = 0.0f;
+    }
+    update();
+}
+
+TQSize LevelMeter::sizeHint() const
+{
+    return TQSize( 8, 48 );
+}
+
+void LevelMeter::paintEvent( TQPaintEvent * )
+{
+    TQPainter p( this );
+    int w = width();
+    int h = height();
+
+    p.fillRect( 0, 0, w, h, TQColor( 40, 40, 40 ) );
+
+    if ( m_level <= 0.0f ) return;
+
+    struct Zone { float lo, hi; TQColor col; };
+    static const Zone zones[3] = {
+        { 0.00f, 0.70f, TQColor(  50, 200,  50 ) },
+        { 0.70f, 0.90f, TQColor( 230, 200,   0 ) },
+        { 0.90f, 1.00f, TQColor( 220,  40,  40 ) },
+    };
+
+    for ( int z = 0; z < 3; z++ ) {
+        if ( m_level <= zones[z].lo ) break;
+        float segEnd = ( m_level < zones[z].hi ) ? m_level : zones[z].hi;
+        int yTop = h - (int)( segEnd      * h );
+        int yBot = h - (int)( zones[z].lo * h );
+        p.fillRect( 0, yTop, w, yBot - yTop, zones[z].col );
+    }
+}