UI: Add new API: _createHiddenButton()

This function creates a hidden clickable area on the editor UI, based on
a dedicated transparent PNG image as the button image of
DGL::ImageButton.

Author: AnClark

src/CetoneUI.cpp

@@ -13,6 +13,7 @@ CCetoneUI::CCetoneUI()
     , fImgKnob(Art::knobData, Art::knobWidth, Art::knobHeight, kImageFormatBGRA)
     , fImgSwitchButton_ON(Art::buttons_onData, Art::buttons_onWidth, Art::buttons_onHeight, kImageFormatBGR)
     , fImgSwitchButton_OFF(Art::buttons_offData, Art::buttons_offWidth, Art::buttons_offHeight, kImageFormatBGR)
+    , fImgTransparent(Art::transparentData, Art::transparentWidth, Art::transparentHeight, kImageFormatBGRA)
 {
     /* Initialize NanoVG font and text buffer */
     NanoVG::FontId font = fNanoText.createFontFromMemory("Source Sans Regular", Fonts::SourceSans3_RegularData, Fonts::SourceSans3_RegularDataSize, false);

src/CetoneUI.hpp

@@ -61,6 +61,7 @@ class CCetoneUI : public DISTRHO::UI,
     Image fImgBackground;
     Image fImgKnob;
     Image fImgSwitchButton_ON, fImgSwitchButton_OFF;
+    Image fImgTransparent;
 
     // -------------------------------------------------------------------
     // Widgets
@@ -99,6 +100,7 @@ class CCetoneUI : public DISTRHO::UI,
     void _createSlider(ScopedPointer<ImageSlider>& slider, uint32_t paramId, uint startPosX, uint startPosY, uint endPosX, uint endPosY, float step, bool inverted = false);
     void _createSwitchButton(ScopedPointer<ImageSwitch>& switchButton, uint32_t paramId, uint absolutePosX, uint absolutePosY);
     void _createButton(ScopedPointer<ImageButton>& button, uint id, Image& imageNormal, Image& imagePressed, uint absolutePosX, uint absolutePosY);
+    void _createHiddenButton(ScopedPointer<ImageButton>& button, uint id, Size<uint> size, Point<int> absolutePos);
 
     const char* _wave2Str(int wave);
     const char* _OscWave2Str(int wave);

src/CetoneUIHelper.cpp

@@ -50,6 +50,15 @@ void CCetoneUI::_createButton(ScopedPointer<ImageButton>& button, uint id, Image
     button->setCallback(this);
 }
 
+void CCetoneUI::_createHiddenButton(ScopedPointer<ImageButton>& button, uint id, Size<uint> size, Point<int> absolutePos)
+{
+    button = new ImageButton(this, fImgTransparent, fImgTransparent);
+    button->setId(id);
+    button->setAbsolutePos(absolutePos);
+    button->setSize(size);
+    button->setCallback(this);
+}
+
 const char* CCetoneUI::_wave2Str(int wave)
 {
     switch (wave) {