GUI: Added a SidePanel component class which is useful for auxiliary UI components on mobile

modules/juce_gui_basics/layout/juce_SidePanel.cpp

@@ -0,0 +1,233 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2017 - ROLI Ltd.
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
+   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
+   27th April 2017).
+
+   End User License Agreement: www.juce.com/juce-5-licence
+   Privacy Policy: www.juce.com/juce-5-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+namespace juce
+{
+
+SidePanel::SidePanel (StringRef title, int width, bool positionOnLeft,
+                      Component* contentToDisplay, bool deleteComponentWhenNoLongerNeeded)
+    : titleLabel ("titleLabel", title),
+      isOnLeft (positionOnLeft),
+      panelWidth (width)
+{
+    lookAndFeelChanged();
+
+    addAndMakeVisible (titleLabel);
+
+    dismissButton.addListener (this);
+    addAndMakeVisible (dismissButton);
+
+    Desktop::getInstance().addGlobalMouseListener (this);
+
+    if (contentToDisplay != nullptr)
+        setContent (contentToDisplay, deleteComponentWhenNoLongerNeeded);
+
+    setOpaque (false);
+}
+
+SidePanel::~SidePanel()
+{
+    if (parent != nullptr)
+        parent->removeComponentListener (this);
+}
+
+void SidePanel::setContent (Component* newContent, bool deleteComponentWhenNoLongerNeeded)
+{
+    if (contentComponent.get() != newContent)
+    {
+        if (deleteComponentWhenNoLongerNeeded)
+            contentComponent.setOwned (newContent);
+        else
+            contentComponent.setNonOwned (newContent);
+
+        addAndMakeVisible (contentComponent);
+    }
+}
+
+void SidePanel::showOrHide (bool show)
+{
+    if (parent != nullptr)
+    {
+        isShowing = show;
+
+        Desktop::getInstance().getAnimator().animateComponent (this, calculateBoundsInParent (*parent),
+                                                               1.0f, 250, true, 1.0, 0.0);
+    }
+}
+
+void SidePanel::resized()
+{
+    auto bounds = getLocalBounds();
+
+    calculateAndRemoveShadowBounds (bounds);
+
+    auto titleBounds = bounds.removeFromTop (titleBarHeight);
+
+    dismissButton.setBounds (isOnLeft ? titleBounds.removeFromRight (30).withTrimmedRight (10)
+                                      : titleBounds.removeFromLeft  (30).withTrimmedLeft  (10));
+
+    titleLabel.setBounds (isOnLeft ? titleBounds.withTrimmedRight (40)
+                                   : titleBounds.withTrimmedLeft (40));
+
+    if (contentComponent != nullptr)
+        contentComponent->setBounds (bounds);
+}
+
+void SidePanel::paint (Graphics& g)
+{
+    auto& lf = getLookAndFeel();
+
+    auto bgColour     = lf.findColour (SidePanel::backgroundColour);
+    auto shadowColour = lf.findColour (SidePanel::shadowBaseColour);
+
+    g.setGradientFill (ColourGradient (shadowColour.withAlpha (0.7f), (isOnLeft ? shadowArea.getTopLeft()
+                                                                                : shadowArea.getTopRight()).toFloat(),
+                                       shadowColour.withAlpha (0.0f), (isOnLeft ? shadowArea.getTopRight()
+                                                                                : shadowArea.getTopLeft()).toFloat(), false));
+    g.fillRect (shadowArea);
+
+    g.excludeClipRegion (shadowArea);
+    g.fillAll (bgColour);
+}
+
+void SidePanel::parentHierarchyChanged()
+{
+    auto* newParent = getParentComponent();
+
+    if ((newParent != nullptr) && (parent != newParent))
+    {
+        if (parent != nullptr)
+            parent->removeComponentListener (this);
+
+        parent = newParent;
+        parent->addComponentListener (this);
+    }
+}
+
+void SidePanel::mouseDrag (const MouseEvent& e)
+{
+    if (shouldResize)
+    {
+        auto currentMouseDragX = static_cast<int> (e.position.x);
+
+        if (isOnLeft)
+        {
+            amountMoved = startingBounds.getRight() - currentMouseDragX;
+            setBounds (getBounds().withX (startingBounds.getX() - jmax (amountMoved, 0)));
+        }
+        else
+        {
+            amountMoved = currentMouseDragX - startingBounds.getX();
+            setBounds (getBounds().withX (startingBounds.getX() + jmax (amountMoved, 0)));
+        }
+    }
+    else
+    {
+        auto relativeMouseDownPosition = getLocalPoint (e.eventComponent, e.getMouseDownPosition());
+        auto relativeMouseDragPosition = getLocalPoint (e.eventComponent, e.getPosition());
+
+        if (! getLocalBounds().contains (relativeMouseDownPosition)
+              && getLocalBounds().contains (relativeMouseDragPosition))
+        {
+            shouldResize = true;
+            startingBounds = getBounds();
+        }
+    }
+}
+
+void SidePanel::mouseUp (const MouseEvent&)
+{
+    if (shouldResize)
+    {
+        showOrHide (amountMoved < (panelWidth / 2));
+
+        amountMoved = 0;
+        shouldResize = false;
+    }
+}
+
+//==========================================================================
+void SidePanel::lookAndFeelChanged()
+{
+    auto& lf = getLookAndFeel();
+
+    dismissButton.setShape (lf.getSidePanelDismissButtonShape (*this), false, true, false);
+
+    dismissButton.setColours (lf.findColour (SidePanel::dismissButtonNormalColour),
+                              lf.findColour (SidePanel::dismissButtonOverColour),
+                              lf.findColour (SidePanel::dismissButtonDownColour));
+
+    titleLabel.setFont (lf.getSidePanelTitleFont (*this));
+    titleLabel.setColour (Label::textColourId, findColour (SidePanel::titleTextColour));
+    titleLabel.setJustificationType (lf.getSidePanelTitleJustification (*this));
+}
+
+void SidePanel::componentMovedOrResized (Component& component, bool wasMoved, bool wasResized)
+{
+    ignoreUnused (wasMoved);
+
+    if (wasResized && (&component == parent))
+        setBounds (calculateBoundsInParent (component));
+}
+
+void SidePanel::buttonClicked (Button*)
+{
+    showOrHide (false);
+}
+
+Rectangle<int> SidePanel::calculateBoundsInParent (Component& parentComp) const
+{
+    auto parentBounds = parentComp.getBounds();
+
+    if (isOnLeft)
+    {
+        return isShowing ? parentBounds.removeFromLeft (panelWidth)
+                         : parentBounds.withX (parentBounds.getX() - panelWidth).withWidth (panelWidth);
+    }
+
+    return isShowing ? parentBounds.removeFromRight (panelWidth)
+                     : parentBounds.withX (parentBounds.getRight()).withWidth (panelWidth);
+}
+
+void SidePanel::calculateAndRemoveShadowBounds (Rectangle<int>& bounds)
+{
+    shadowArea = isOnLeft ? bounds.removeFromRight (shadowWidth)
+                          : bounds.removeFromLeft  (shadowWidth);
+}
+
+bool SidePanel::isMouseEventInThisOrChildren (Component* eventComponent)
+{
+    if (eventComponent == this)
+        return true;
+
+    for (auto& child : getChildren())
+        if (eventComponent == child)
+            return true;
+
+    return false;
+}
+
+} // namespace juce