Fix resizing on Linux

Makefile

@@ -50,6 +50,7 @@ include hiphop/Makefile.plugins.mk
 
 TARGETS += lv2_sep vst vst3
 
+LXHELPER_CPPFLAGS += -Isrc
 BASE_FLAGS += -Isrc
 
 # Required for soundpipe.h

src/DistrhoPluginInfo.h

@@ -14,6 +14,11 @@
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+/**
+   Make room for growing the UI on Linux/GTK
+ */
+#define HIPHOP_UI_USER_RESIZABLE 1
+
 /**
    The plugin name.@n
    This is used to identify your plugin before a Plugin instance can be created.

src/ui/style.css

@@ -22,7 +22,7 @@ body {
     margin: 0;
     background-color: #8c8c8c;
     color: #000000;
-    position: relative; /* for the resize handle */
+    position: relative;
 }
 
 g-knob {

src/ui/ui.js

@@ -57,13 +57,13 @@ class CastelloReverbUI extends DISTRHO.UI {
         // Setting up resize handle needs calling async methods
 
         (async () => {
-            const w = await this.getInitWidth(),
+            const w = await this.getInitWidth(),  // CSS pixels
                   h = await this.getInitHeight();
 
             resize.opt.minWidth = w;
             resize.opt.minHeight = h;
 
-            this.sizeChanged(w, h);
+            this._sizeChanged();
 
             document.body.style.visibility = 'visible';
         }) ();
@@ -95,15 +95,17 @@ class CastelloReverbUI extends DISTRHO.UI {
         }
     }
 
+    sizeChanged(width, height) {
+        this._sizeChanged();
+    }
+
     /* It is not currently possible to rely on vh/vw/vmin/vmax units on Linux
        due to the GTK web view implementation on such platform */
 
-    sizeChanged(width, height) {
+    _sizeChanged() {
         if (DISTRHO.env.noCSSViewportUnits) {
-            height /= window.devicePixelRatio;
-
             document.querySelectorAll('g-knob').forEach(((el) => {
-                el.style.height = (0.3 * height) + 'px';
+                el.style.height = (0.3/*30vh*/ * document.body.clientHeight) + 'px';
                 el.style.width = el.style.height;
             }));
         }
@@ -114,9 +116,9 @@ class CastelloReverbUI extends DISTRHO.UI {
             this.setParameterValue(parameterIndex, ev.target.value);
         });
 
-        function updateLabel(value) {
+        const updateLabel = (value) => {
             el.parentNode.children[2].innerText = labelFormatCallback(value);
-        }
+        };
 
         el.addEventListener('setvalue', (ev) => updateLabel(ev.value));