use visual insets instead of spacers for edge keys (fixes #308, #294)

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/Key.java

@@ -947,6 +947,8 @@ public class Key implements Comparable<Key> {
         private final KeyboardParams mKeyboardParams; // for reading gaps and keyboard width / height
         public float mRelativeWidth;
         public float mRelativeHeight; // also should allow negative values, indicating absolute height is defined
+        public float mRelativeVisualInsetLeft;
+        public float mRelativeVisualInsetRight;
 
         // params that may change
         public float mFullWidth;
@@ -965,7 +967,7 @@ public class Key implements Comparable<Key> {
         public final int mBackgroundType;
         public final int mActionFlags;
         @Nullable public final KeyVisualAttributes mKeyVisualAttributes;
-        @Nullable public final OptionalAttributes mOptionalAttributes;
+        @Nullable public OptionalAttributes mOptionalAttributes;
         public final boolean mEnabled;
 
         public static KeyParams newSpacer(final TypedArray keyAttr, final KeyStyle keyStyle,
@@ -999,6 +1001,18 @@ public class Key implements Comparable<Key> {
             yPos = newY;
             mFullWidth = mRelativeWidth * mKeyboardParams.mBaseWidth;
             mFullHeight = mRelativeHeight * mKeyboardParams.mBaseHeight;
+
+            // set visual insets if any
+            if (mRelativeVisualInsetRight != 0f || mRelativeVisualInsetLeft != 0f) {
+                final int insetLeft = (int) (mRelativeVisualInsetLeft * mKeyboardParams.mBaseWidth);
+                final int insetRight = (int) (mRelativeVisualInsetRight * mKeyboardParams.mBaseWidth);
+                if (mOptionalAttributes == null) {
+                    mOptionalAttributes = OptionalAttributes.newInstance(null, CODE_UNSPECIFIED, ICON_UNDEFINED, insetLeft, insetRight);
+                } else {
+                    mOptionalAttributes = OptionalAttributes
+                            .newInstance(mOptionalAttributes.mOutputText, mOptionalAttributes.mAltCode, mOptionalAttributes.mDisabledIconId, insetLeft, insetRight);
+                }
+            }
         }
 
         private static int getMoreKeysColumnAndFlagsAndSetNullInArray(final KeyboardParams params, final String[] moreKeys) {
@@ -1298,7 +1312,6 @@ public class Key implements Comparable<Key> {
                     : altCodeInAttr;
             mOptionalAttributes = OptionalAttributes.newInstance(outputText, altCode,
                     // disabled icon only ever for old version of shortcut key, visual insets can be replaced with spacer
-                    // todo (much later): can the 3 below be removed completely?
                     KeyboardIconsSet.ICON_UNDEFINED, 0, 0);
             // KeyVisualAttributes for a key essentially are what the theme has, but on a per-key base
             // could be used e.g. for having a color gradient on key color

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/KeyboardBuilder.kt

@@ -164,7 +164,7 @@ open class KeyboardBuilder<KP : KeyboardParams>(protected val mContext: Context,
             if (loadFromAssets(id) != null) {
                 if (!DebugFlags.DEBUG_ENABLED)
                     return this
-                // comparison of old and new parser below, remove once testing is complete
+                // comparison of old and new parser below, todo: remove once testing is complete
                 val keysInRowsFromXml = XmlKeyboardParser(xmlId, mParams, mContext).use { keyboardParser ->
                     keyboardParser.parseKeyboard()
                 }

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/internal/keyboard_parser/KeyboardParser.kt

@@ -115,7 +115,8 @@ abstract class KeyboardParser(private val params: KeyboardParams, private val co
                 spacerWidth = 0f
                 keyWidth = availableWidth / row.size
             }
-            if (spacerWidth != 0f) {
+            if (spacerWidth != 0f && functionalKeysLeft.isNotEmpty()) {
+                // add a spacer between left functional key and keyboard key
                 paramsRow.add(KeyParams.newSpacer(params, spacerWidth))
             }
             if (keyWidth < params.mDefaultRelativeKeyWidth * 0.82 && spacerWidth == 0f) {
@@ -137,7 +138,25 @@ abstract class KeyboardParser(private val params: KeyboardParams, private val co
                     Log.d(TAG, "adding key ${keyParams.mLabel}, ${keyParams.mCode}")
             }
             if (spacerWidth != 0f) {
-                paramsRow.add(KeyParams.newSpacer(params, spacerWidth))
+                // todo: the spacer-or-key-extension logic should go into a separate function
+                if (functionalKeysLeft.isEmpty()) {
+                    // we did not add a spacer above, but extend the key to the edge and set visual insets
+                    paramsRow.first().mRelativeWidth += spacerWidth
+                    paramsRow.first().mRelativeVisualInsetLeft = spacerWidth
+                }
+                if (functionalKeysRight.isEmpty()) {
+                    // extend right key to the edge and set visual insets
+                    paramsRow.last().mRelativeWidth += spacerWidth
+                    paramsRow.last().mRelativeVisualInsetRight = spacerWidth
+                } else {
+                    // add a spacer between keyboard key and right functional key (like for the left side)
+                    // unless it's the enter key, in that case increase the key's width (to match original layout in tablet mode)
+                    if (functionalKeysRight.singleOrNull()?.mBackgroundType == Key.BACKGROUND_TYPE_ACTION) {
+                        functionalKeysRight.single().mRelativeWidth += spacerWidth
+                    } else {
+                        paramsRow.add(KeyParams.newSpacer(params, spacerWidth))
+                    }
+                }
             }
             functionalKeysRight.forEach { paramsRow.add(it) }
             keysInRows.add(0, paramsRow) // we're doing it backwards, so add on top