Add basic slider control

ui/ui_screen.cpp

@@ -108,3 +108,9 @@ UI::EventReturn ListPopupScreen::OnListChoice(UI::EventParams &e) {
 void ListPopupScreen::OnCompleted() {
 	callback_(adaptor_.GetSelected());	
 }
+
+
+void SliderPopupScreen::CreatePopupContents(UI::ViewGroup *parent) {
+	using namespace UI;
+	slider_ = parent->Add(new Slider(value_, minValue_, maxValue_));
+}

ui/ui_screen.h

@@ -66,3 +66,15 @@ private:
 
 	std::function<void(int)> callback_;
 };
+
+class SliderPopupScreen : public PopupScreen {
+public:
+	SliderPopupScreen(int *value, int minValue, int maxValue, const std::string &title) : PopupScreen(title), value_(value), minValue_(minValue), maxValue_(maxValue) {}
+	void CreatePopupContents(UI::ViewGroup *parent);
+
+private:
+	UI::Slider *slider_;
+	int *value_;
+	int minValue_;
+	int maxValue_;
+};

ui/view.cpp

@@ -2,6 +2,7 @@
 #include "base/display.h"
 #include "base/mutex.h"
 #include "input/input_state.h"
+#include "input/keycodes.h"
 #include "gfx_es2/draw_buffer.h"
 #include "gfx/texture.h"
 #include "gfx/texture_atlas.h"
@@ -418,6 +419,50 @@ void TriggerButton::GetContentDimensions(const UIContext &dc, float &w, float &h
 	h = image.h;
 }
 
+void Slider::Key(const KeyInput &input) {
+	if (HasFocus() && input.flags & KEY_DOWN) {
+		switch (input.keyCode) {
+		case KEYCODE_DPAD_LEFT:
+		case KEYCODE_MINUS:
+		case KEYCODE_NUMPAD_SUBTRACT:
+			*value_ -= 1;
+			break;
+		case KEYCODE_DPAD_RIGHT:
+		case KEYCODE_PLUS:
+		case KEYCODE_NUMPAD_ADD:
+			*value_ -= 1;
+			break;
+		}
+		Clamp();
+	}
+}
+
+void Slider::Touch(const TouchInput &input) {
+	if (dragging_ || bounds_.Contains(input.x, input.y)) {
+		float relativeX = (input.x - bounds_.x) / bounds_.w;
+		*value_ = floorf(relativeX * (maxValue_ - minValue_) + minValue_ + 0.5f);
+		Clamp();
+	}
+}
+
+void Slider::Clamp() {
+	if (*value_ < minValue_) *value_ = minValue_;
+	else if (*value_ > maxValue_) *value_ = maxValue_;
+}
+
+void Slider::Draw(UIContext &dc) {
+	float knobX = ((float)(*value_) - minValue_) / (maxValue_ - minValue_) * bounds_.w + bounds_.x;
+	dc.FillRect(Drawable(0xFFFFFFFF), Bounds(bounds_.x, bounds_.centerY() - 2, knobX - bounds_.x, 4));
+	dc.FillRect(Drawable(0xFF808080), Bounds(knobX, bounds_.centerY() - 2, bounds_.x + bounds_.w - knobX, 4));
+	dc.Draw()->DrawImage(dc.theme->sliderKnob, knobX, bounds_.centerY(), 1.0f, 0xFFFFFFFF, ALIGN_CENTER);
+}
+
+void Slider::GetContentDimensions(const UIContext &dc, float &w, float &h) const {
+	// TODO
+	w = 100;
+	h = 50;
+}
+
 
 /*
 TabStrip::TabStrip()

ui/view.h

@@ -79,6 +79,7 @@ struct Theme {
 	int uiFontSmaller;
 	int checkOn;
 	int checkOff;
+	int sliderKnob;
 	int whiteImage;
 
 	Style buttonStyle;
@@ -401,6 +402,23 @@ private:
 	std::string text_;
 };
 
+class Slider : public Clickable {
+public:
+	Slider(int *value, int minValue, int maxValue, LayoutParams *layoutParams = 0)
+		: Clickable(layoutParams), value_(value), minValue_(minValue), maxValue_(maxValue) {}
+	virtual void Draw(UIContext &dc);
+	virtual void Key(const KeyInput &input);
+	virtual void Touch(const TouchInput &input);
+	virtual void GetContentDimensions(const UIContext &dc, float &w, float &h) const;
+
+private:
+	void Clamp();
+	int *value_;
+	int minValue_;
+	int maxValue_;
+};
+
+
 // Basic button that modifies a bitfield based on the pressed status. Supports multitouch.
 // Suitable for controller simulation (ABXY etc).
 class TriggerButton : public View {
@@ -517,7 +535,6 @@ private:
 	std::string smallText_;
 };
 
-
 // These are for generic use.
 
 class Spacer : public InertView {