Enable -Wshadow for input code

To avoid common programming mistakes, enable -Wshadow for input code.
This requires several refactors, such as using range-based for loops and
avoiding repeating variable names that are already in scope.

To allow for -Wshadow, we convert to unordered_map and use a range-based
loop.

Bug: 142017994
Test: atest libinput_tests inputflinger_tests
Change-Id: Icb65045d3322eccc312bca63287e38897d9f9ff6
diff --git a/services/inputflinger/reader/mapper/JoystickInputMapper.cpp b/services/inputflinger/reader/mapper/JoystickInputMapper.cpp
index b2e10d6..bf81496 100644
--- a/services/inputflinger/reader/mapper/JoystickInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/JoystickInputMapper.cpp
@@ -32,8 +32,8 @@
 void JoystickInputMapper::populateDeviceInfo(InputDeviceInfo* info) {
     InputMapper::populateDeviceInfo(info);
 
-    for (size_t i = 0; i < mAxes.size(); i++) {
-        const Axis& axis = mAxes.valueAt(i);
+    for (std::pair<const int32_t, Axis>& pair : mAxes) {
+        const Axis& axis = pair.second;
         addMotionRange(axis.axisInfo.axis, axis, info);
 
         if (axis.axisInfo.mode == AxisInfo::MODE_SPLIT) {
@@ -72,9 +72,7 @@
     dump += INDENT2 "Joystick Input Mapper:\n";
 
     dump += INDENT3 "Axes:\n";
-    size_t numAxes = mAxes.size();
-    for (size_t i = 0; i < numAxes; i++) {
-        const Axis& axis = mAxes.valueAt(i);
+    for (const auto& [rawAxis, axis] : mAxes) {
         const char* label = getAxisLabel(axis.axisInfo.axis);
         if (label) {
             dump += StringPrintf(INDENT4 "%s", label);
@@ -100,7 +98,7 @@
                              axis.scale, axis.offset, axis.highScale, axis.highOffset);
         dump += StringPrintf(INDENT4 "  rawAxis=%d, rawMin=%d, rawMax=%d, "
                                      "rawFlat=%d, rawFuzz=%d, rawResolution=%d\n",
-                             mAxes.keyAt(i), axis.rawAxisInfo.minValue, axis.rawAxisInfo.maxValue,
+                             rawAxis, axis.rawAxisInfo.minValue, axis.rawAxisInfo.maxValue,
                              axis.rawAxisInfo.flat, axis.rawAxisInfo.fuzz,
                              axis.rawAxisInfo.resolution);
     }
@@ -130,9 +128,7 @@
                     axisInfo.mode = AxisInfo::MODE_NORMAL;
                     axisInfo.axis = -1;
                 }
-
-                Axis axis = createAxis(axisInfo, rawAxisInfo, explicitlyMapped);
-                mAxes.add(abs, axis);
+                mAxes.insert({abs, createAxis(axisInfo, rawAxisInfo, explicitlyMapped)});
             }
         }
 
@@ -147,9 +143,8 @@
 
         // Assign generic axis ids to remaining axes.
         int32_t nextGenericAxisId = AMOTION_EVENT_AXIS_GENERIC_1;
-        size_t numAxes = mAxes.size();
-        for (size_t i = 0; i < numAxes; i++) {
-            Axis& axis = mAxes.editValueAt(i);
+        for (auto it = mAxes.begin(); it != mAxes.end(); /*increment it inside loop*/) {
+            Axis& axis = it->second;
             if (axis.axisInfo.axis < 0) {
                 while (nextGenericAxisId <= AMOTION_EVENT_AXIS_GENERIC_16 &&
                        haveAxis(nextGenericAxisId)) {
@@ -162,11 +157,12 @@
                 } else {
                     ALOGI("Ignoring joystick '%s' axis %d because all of the generic axis ids "
                           "have already been assigned to other axes.",
-                          getDeviceName().c_str(), mAxes.keyAt(i));
-                    mAxes.removeItemsAt(i--);
-                    numAxes -= 1;
+                          getDeviceName().c_str(), it->first);
+                    it = mAxes.erase(it);
+                    continue;
                 }
             }
+            it++;
         }
     }
 }
@@ -177,38 +173,41 @@
     // Apply flat override.
     int32_t rawFlat = axisInfo.flatOverride < 0 ? rawAxisInfo.flat : axisInfo.flatOverride;
 
+    float scale = std::numeric_limits<float>::signaling_NaN();
+    float highScale = std::numeric_limits<float>::signaling_NaN();
+    float highOffset = 0;
+    float offset = 0;
+    float min = 0;
     // Calculate scaling factors and limits.
-    Axis axis;
     if (axisInfo.mode == AxisInfo::MODE_SPLIT) {
-        float scale = 1.0f / (axisInfo.splitValue - rawAxisInfo.minValue);
-        float highScale = 1.0f / (rawAxisInfo.maxValue - axisInfo.splitValue);
-        axis.initialize(rawAxisInfo, axisInfo, explicitlyMapped, scale, 0.0f, highScale, 0.0f, 0.0f,
-                        1.0f, rawFlat * scale, rawAxisInfo.fuzz * scale,
-                        rawAxisInfo.resolution * scale);
+        scale = 1.0f / (axisInfo.splitValue - rawAxisInfo.minValue);
+        highScale = 1.0f / (rawAxisInfo.maxValue - axisInfo.splitValue);
     } else if (isCenteredAxis(axisInfo.axis)) {
-        float scale = 2.0f / (rawAxisInfo.maxValue - rawAxisInfo.minValue);
-        float offset = avg(rawAxisInfo.minValue, rawAxisInfo.maxValue) * -scale;
-        axis.initialize(rawAxisInfo, axisInfo, explicitlyMapped, scale, offset, scale, offset,
-                        -1.0f, 1.0f, rawFlat * scale, rawAxisInfo.fuzz * scale,
-                        rawAxisInfo.resolution * scale);
+        scale = 2.0f / (rawAxisInfo.maxValue - rawAxisInfo.minValue);
+        offset = avg(rawAxisInfo.minValue, rawAxisInfo.maxValue) * -scale;
+        highOffset = offset;
+        highScale = scale;
+        min = -1.0f;
     } else {
-        float scale = 1.0f / (rawAxisInfo.maxValue - rawAxisInfo.minValue);
-        axis.initialize(rawAxisInfo, axisInfo, explicitlyMapped, scale, 0.0f, scale, 0.0f, 0.0f,
-                        1.0f, rawFlat * scale, rawAxisInfo.fuzz * scale,
-                        rawAxisInfo.resolution * scale);
+        scale = 1.0f / (rawAxisInfo.maxValue - rawAxisInfo.minValue);
+        highScale = scale;
     }
 
+    constexpr float max = 1.0;
+    const float flat = rawFlat * scale;
+    const float fuzz = rawAxisInfo.fuzz * scale;
+    const float resolution = rawAxisInfo.resolution * scale;
+
     // To eliminate noise while the joystick is at rest, filter out small variations
     // in axis values up front.
-    axis.filter = axis.fuzz ? axis.fuzz : axis.flat * 0.25f;
-
-    return axis;
+    const float filter = fuzz ? fuzz : flat * 0.25f;
+    return Axis(rawAxisInfo, axisInfo, explicitlyMapped, scale, offset, highScale, highOffset, min,
+                max, flat, fuzz, resolution, filter);
 }
 
 bool JoystickInputMapper::haveAxis(int32_t axisId) {
-    size_t numAxes = mAxes.size();
-    for (size_t i = 0; i < numAxes; i++) {
-        const Axis& axis = mAxes.valueAt(i);
+    for (const std::pair<int32_t, Axis>& pair : mAxes) {
+        const Axis& axis = pair.second;
         if (axis.axisInfo.axis == axisId ||
             (axis.axisInfo.mode == AxisInfo::MODE_SPLIT && axis.axisInfo.highAxis == axisId)) {
             return true;
@@ -218,14 +217,14 @@
 }
 
 void JoystickInputMapper::pruneAxes(bool ignoreExplicitlyMappedAxes) {
-    size_t i = mAxes.size();
-    while (mAxes.size() > PointerCoords::MAX_AXES && i-- > 0) {
-        if (ignoreExplicitlyMappedAxes && mAxes.valueAt(i).explicitlyMapped) {
+    while (mAxes.size() > PointerCoords::MAX_AXES) {
+        auto it = mAxes.begin();
+        if (ignoreExplicitlyMappedAxes && it->second.explicitlyMapped) {
             continue;
         }
         ALOGI("Discarding joystick '%s' axis %d because there are too many axes.",
-              getDeviceName().c_str(), mAxes.keyAt(i));
-        mAxes.removeItemsAt(i);
+              getDeviceName().c_str(), it->first);
+        mAxes.erase(it);
     }
 }
 
@@ -250,9 +249,8 @@
 
 void JoystickInputMapper::reset(nsecs_t when) {
     // Recenter all axes.
-    size_t numAxes = mAxes.size();
-    for (size_t i = 0; i < numAxes; i++) {
-        Axis& axis = mAxes.editValueAt(i);
+    for (std::pair<const int32_t, Axis>& pair : mAxes) {
+        Axis& axis = pair.second;
         axis.resetValue();
     }
 
@@ -262,9 +260,9 @@
 void JoystickInputMapper::process(const RawEvent* rawEvent) {
     switch (rawEvent->type) {
         case EV_ABS: {
-            ssize_t index = mAxes.indexOfKey(rawEvent->code);
-            if (index >= 0) {
-                Axis& axis = mAxes.editValueAt(index);
+            auto it = mAxes.find(rawEvent->code);
+            if (it != mAxes.end()) {
+                Axis& axis = it->second;
                 float newValue, highNewValue;
                 switch (axis.axisInfo.mode) {
                     case AxisInfo::MODE_INVERT:
@@ -324,9 +322,8 @@
     PointerCoords pointerCoords;
     pointerCoords.clear();
 
-    size_t numAxes = mAxes.size();
-    for (size_t i = 0; i < numAxes; i++) {
-        const Axis& axis = mAxes.valueAt(i);
+    for (std::pair<const int32_t, Axis>& pair : mAxes) {
+        const Axis& axis = pair.second;
         setPointerCoordsAxisValue(&pointerCoords, axis.axisInfo.axis, axis.currentValue);
         if (axis.axisInfo.mode == AxisInfo::MODE_SPLIT) {
             setPointerCoordsAxisValue(&pointerCoords, axis.axisInfo.highAxis,
@@ -364,9 +361,8 @@
 
 bool JoystickInputMapper::filterAxes(bool force) {
     bool atLeastOneSignificantChange = force;
-    size_t numAxes = mAxes.size();
-    for (size_t i = 0; i < numAxes; i++) {
-        Axis& axis = mAxes.editValueAt(i);
+    for (std::pair<const int32_t, Axis>& pair : mAxes) {
+        Axis& axis = pair.second;
         if (force ||
             hasValueChangedSignificantly(axis.filter, axis.newValue, axis.currentValue, axis.min,
                                          axis.max)) {